Electrolytic process for treating a conductive surface and products formed thereby

ABSTRACT

The disclosure relates to a process for forming a deposit on the surface of a metallic or conductive surface. The process employs an electrolytic process to deposit a silicate containing coating or film upon a metallic or conductive surface.

[0001] The subject matter herein claims benefit of U.S. patentapplication Ser. No. 09/532,982, filed on Mar. 22, 2000 that is acontinuation in part of Ser. No. 09/369,780, filed on Aug. 06, 1999 (nowU.S. Pat. No. 6,153,080) that is a continuation in part of Ser. No.09/122,002, filed on Jul. 24, 1998 that is a continuation in part ofSer. No. 09/016,250, filed on Jan. 30, 1998 (now U.S. Pat. No.6,149,794) in the names of Robert L. Heimann et al. and entitled “AnElectrolytic Process For Forming A Mineral”; the entire disclosures ofwhich are hereby incorporated by reference. The subject matter of thisinvention claims benefit under 35 U.S.C. 111(a), 35 U.S.C. 119(e) and 35U.S.C. 120 of U.S. Provisional Patent Application Ser. No. 60/036,024,filed on Jan. 31, 1997 and Ser. No. 60/045,446, filed on May 2, 1997 andentitled “Non-Equilibrium Enhanced Mineral Deposition”. The disclosureof the previously filed provisional patent applications is herebyincorporated by reference.

FIELD OF THE INVENTION

[0002] The instant invention relates to a process for forming a depositon the surface of a metallic or conductive surface. The process employsan electrolytic process to deposit, for example, a mineral containingcoating or film upon a metallic, metal containing or an electricallyconductive surface.

BACKGROUND OF THE INVENTION

[0003] Silicates have been used in electrocleaning operations to cleansteel, tin, among other surfaces. Electrocleaning is typically employedas a cleaning step prior to an electroplating operation. Using“Silicates As Cleaners In The Production of Tinplate” is described by L.J. Brown in February 1966 edition of Plating; hereby incorporated byreference.

[0004] Processes for electrolytically forming a protective layer or filmby using an anodic method are disclosed by U.S. Pat. No. 3,658,662(Casson, Jr. et al.), and United Kingdom Patent No. 498,485; both ofwhich are hereby incorporated by reference.

[0005] U.S. Pat. No. 5,352,342 to Riffe, which issued on Oct. 4, 1994and is entitled “Method And Apparatus For Preventing Corrosion Of MetalStructures” that describes using electromotive forces upon a zincsolvent containing paint; hereby incorporated by reference.

SUMMARY OF THE INVENTION

[0006] The instant invention solves problems associated withconventional practices by providing a cathodic method for forming aprotective layer upon a metallic or metal containing substrate (e.g.,the protective layer can range from about 100 to about 2,500 Angstromsthick). The cathodic method is normally conducted by contacting (e.g.,immersing) a substrate having an electrically conductive surface into asilicate containing bath or medium wherein a current is introduced to(e.g., passed through) the bath and the substrate is the cathode.

[0007] The inventive process can form a mineral layer comprising anamorphous matrix surrounding or incorporating metal silicate crystalsupon the substrate. The characteristics of the mineral layer aredescribed in greater detail in the copending and commonly assignedpatent applications listed below.

[0008] An electrically conductive surface that is treated (e.g., formingthe mineral layer) by the inventive process can possess improvedcorrosion resistance, increased electrical resistance, heat resistance,flexibility, resistance to stress crack corrosion, adhesion to topcoats,among other properties. The treated surface imparts greater corrosionresistance (e.g., ASTM B-117), among other beneficial properties, thanconventional tri-valent or hexa-valent chromate systems. The inventiveprocess can provide a zinc-plate article having an ASTM B-117 resistanceto white rust of at least about 72 hours (and normally greater thanabout 96 hours), and resistance to red rust of at least about 168 (andnormally greater than about 400 hours). The corrosion resistance can beimproved by using a rinse and/or applying at least one topcoating.

[0009] The inventive process is a marked improvement over conventionalmethods by obviating the need for solvents or solvent containing systemsto form a corrosion resistant layer, e.g., a mineral layer. In contrast,to conventional methods the inventive process can be substantiallysolvent free. By “substantially solvent free” it is meant that less thanabout 5 wt. %, and normally less than about 1 wt. % volatile organiccompounds (V.O.C.s) are present in the electrolytic environment.

[0010] The inventive process is also a marked improvement overconventional methods by reducing, if not eliminating, chromate and/orphosphate containing compounds (and issues attendant with using thesecompounds such as waste disposal, worker exposure, among otherundesirable environmental impacts). While the inventive process can beemployed to enhance chromated or phosphated surfaces, the inventiveprocess can replace these surfaces with a more environmentally desirablesurface. The inventive process, therefore, can be “substantiallychromate free” and “substantially phosphate free” and in turn producearticles that are also substantially chromate (hexavalent and trivalent)free and substantially phosphate free. The inventive process can also besubstantially free of heavy metals such as chromium, lead, cadmium,cobalt, barium, among others. By substantially chromate free,substantially phosphate free and substantially heavy metal free it ismeant that less than 5 wt. % and normally about 0 wt. % chromates,phosphates and/or heavy metals are present in a process for producing anarticle or the resultant article. In addition to obviating chromatecontaining processes, the inventive method forms a layer having greaterheat resistance, flexibility, among other properties, than conventionalchromate coatings. The improved heat resistance broadens the range ofprocesses that can be performed subsequent to forming the inventivelayer, e.g., heat cured topcoatings, stamping/shaping, riveting, amongother processes.

[0011] In contrast to conventional electrocleaning processes, theinstant invention employs silicates in a cathodic process for forming amineral layer upon the substrate. Conventional electro-cleaningprocesses sought to avoid formation of oxide containing products such asgreenalite whereas the instant invention relates to a method for formingsilicate containing products, e.g., a mineral.

CROSS REFERENCE TO RELATED PATENTS AND PATENT APPLICATIONS

[0012] The subject matter of the instant invention is related tocopending and commonly assigned WIPO Patent Application Publication No.WO 98/33960, Non-Provisional U.S. Patent Application Ser. No. 08/850,323(Now U.S. Pat. No. 6,165,257); Ser. No. 08/850,586 (Now U.S. Pat. No.6,143,420); and Ser. No. 09/016,853 (now allowed), filed respectively onMay 2, 1997 and Jan. 30, 1998, and Ser. No. 08/791,337 (now U.S. Pat. No5,938,976), filed on Jan. 31, 1997, in the names of Robert L. Heimann etal., as a continuation in part of Ser. No. 08/634,215 (filed on Apr. 18,1996) in the names of Robert L. Heimann et al., and entitled “CorrosionResistant Buffer System for Metal Products”, which is a continuation inpart of Non-Provisional U.S. Patent Application Ser. No. 08/476,271(filed on Jun. 7, 1995) in the names of Heimann et al., andcorresponding to WIPO Patent Application Publication No. WO 96/12770,which in turn is a continuation in part of Non-Provisional U.S. PatentApplication Ser. No. 08/327,438 (filed on Oct. 21, 1994), now U.S. Pat.No. 5,714,093.

[0013] The subject matter of this invention is related toNon-Provisional Patent Application Ser. No. 09/016,849 (Attorney DocketNo. EL004RH-1), filed on Jan. 30, 1998 and entitled “CorrosionProtective Coatings”. The subject matter of this invention is alsorelated to Non-Provisional Patent Application Ser. No. 09/016,462(Attorney Docket No. EL005NM-1), filed on Jan. 30, 1998 and entitled“Aqueous Gel Compositions and Use Thereof” (now U.S. Pat. No.6,033,495). The disclosure of the previously identified patents, patentapplications and publications is hereby incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWING

[0014]FIG. 1 is a schematic drawing of the circuit and apparatus whichcan be employed for practicing an aspect of the invention.

[0015]FIG. 2 is a schematic drawing of one process that employs theinventive electrolytic method.

DETAILED DESCRIPTION

[0016] The instant invention relates to a process for depositing orforming a beneficial surface (e.g., a mineral containing coating orfilm) upon a metallic or an electrically conductive surface. The processemploys a silicate medium, e.g., containing soluble mineral componentsor precursors thereof, and utilizes an electrically enhanced method totreat an electrically conductive surface (e.g., to obtain a mineralcoating or film upon a metallic or conductive surface). By “mineralcontaining coating”, “mineralized film” or “mineral” it is meant torefer to a relatively thin coating or film which is formed upon a metalor conductive surface wherein at least a portion of the coating or filmcomprises at least one metal containing mineral, e.g., an amorphousphase or matrix surrounding or incorporating crystals comprising a zincdisilicate. Mineral and Mineral Containing are defined in the previouslyidentified Copending and Commonly Assigned Patents and PatentApplications; incorporated by reference. By “electrolytic” or“electrodeposition” or “electrically enhanced”, it is meant to refer toan environment created by introducing or passing an electrical currentthrough a silicate containing medium while in contact with anelectrically conductive substrate (or having an electrically conductivesurface) and wherein the substrate functions as the cathode. By “metalcontaining”, “metal”, or “metallic”, it is meant to refer to sheets,shaped articles, fibers, rods, particles, continuous lengths such ascoil and wire, metallized surfaces, among other configurations that arebased upon at least one metal and alloys including a metal having anaturally occurring, or chemically, mechanically or thermally modifiedsurface. Typically a naturally occurring surface upon a metal willcomprise a thin film or layer comprising at least one oxide, hydroxides,carbonates, among others. The naturally occurring surface can be removedor modified by using the inventive process.

[0017] The electrolytic environment can be established in any suitablemanner including immersing the substrate, applying a silicate containingcoating upon the substrate and thereafter applying an electricalcurrent, among others. The preferred method for establishing theenvironment will be determined by the size of the substrate,electrodeposition time, applied voltage, among other parameters known inthe electrodeposition art. The inventive process can be operated on abatch or continuous basis.

[0018] The silicate containing medium can be a fluid bath, gel, spray,among other methods for contacting the substrate with the silicatemedium. Examples of the silicate medium comprise a bath containing atleast one silicate, a gel comprising at least one silicate and athickener, among others. The medium can comprise a bath comprising atleast one of potassium silicate, calcium silicate, lithium silicate,sodium silicate, compounds releasing silicate moieties or species, amongother silicates. Normally, the bath comprises sodium silicate andde-ionized water and optionally at least one dopant. Typically, the atleast one dopant is water soluble or dispersible within an aqueousmedium.

[0019] The silicate containing medium typically has a basic pH.Normally, the pH will range from greater than about 9 to about 13 andtypically, about 10 to about 11. The medium is normally aqueous and cancomprise at least one water soluble or dispersible silicate in an amountfrom greater than 0 to about 40 wt. %, usually, about 3 to 15 wt. % andtypically about 10 wt. %. The silicate medium can further comprise atleast one water dispersible or soluble dopant. The silicate containing 0medium is also normally substantially free of heavy metals, chromatesand/or phosphates.

[0020] The electrolytic environment can be preceded by or followed withconventional post and/or pre-treatments known in this art such ascleaning or rinsing, e.g., immersion/spray within the treatment, soniccleaning, double counter-current cascading flow; alkali or acidtreatments, among other treatments. By employing a suitablepost-treatment the solubility, corrosion resistance (e.g., reduced whiterust formation when treating zinc containing surfaces), topcoatadhesion, among other properties of surface of the substrate formed bythe inventive method can be improved. If desired, the post-treatedsurface can be rinsed or topcoated, e.g., silane, epoxy, latex,fluoropolymer, acrylic, titanates, zirconates, carbontes, among othercoatings.

[0021] In one aspect of the invention, a pre-treatment comprisesexposing the substrate to be treated to at least one of an acid,oxidizer, among other compounds. The pre-treatment can be employed forremoving excess oxides or scale, equipotentialize the surface forsubsequent mineralization treatments, convert the surface into a mineralprecursor, among other benefits.

[0022] In one aspect of the invention, the post treatment comprisesexposing the substrate to a source of at least one carbonate orprecursors thereof. Examples of carbonate comprise at least one memberfrom the group of gaseous carbon dioxide, lithium carbonate, lithiumbicarbonate, sodium carbonate, sodium bicarbonate, potassium carbonate,potassium bicarbonate, rubidium carbonate, rubidium bicarbonate,rubidium acid carbonate, cesium carbonate, ammonium carbonate, ammoniumbicarbonate, ammonium carbamate and ammonium zirconyl carbonate.Normally, the carbonate source will be water soluble. In the case of acarbonate precursor such as carbon dioxide, the precursor can be passedthrough a liquid (including the silicate containing medium) and thesubstrate immersed in the liquid. One specific example of a suitablepostreatment is disclosed in U.S. Pat. No. 2,462,763; herebyincorporated by reference. Another specific example of a post treatmentcomprises exposing a treated surface to a solution obtained by dilutingammonium zirconyl carbonate (1:4) in distilled water (e.g., Bacote® 20supplied by Magnesium Elektron Corp). If desired, this post treatedsurface can be topcoated (e.g., aqueous or water borne topcoats).

[0023] In another aspect of the invention, the post treatment comprisesexposing the substrate to a source comprising at least one acid sourceor precursors thereof. Examples of suitable acid sources comprise atleast one member chosen from the group of phosphoric acid, hydrochloricacid, molybdic acid, silicic acid, acetic acid, among other acid sourceseffective at improving at least one property of the treated metalsurface. Normally, the acid source will be water soluble and employed inamounts of up to about 5 wt. % and typically, about 1 to about 2 wt. %.

[0024] In another aspect of the invention, the post treatment comprisescontacting a surface treated by the inventive process with a rinse. By“rinse” it is meant that an article or a treated surface is sprayed,dipped, immersed or other wise exposed to the rinse in order to affectthe properties of the treated surface. For example, a surface treated bythe inventive process is immersed in a bath comprising at least onerinse. In some cases, the rinse can interact or react with at least aportion of the treated surface. Further the rinsed surfaced can bemodified by multiple rinses, heating, topcoating, adding dyes,lubricants and waxes, among other processes. Examples of suitablecompounds for use in rinses comprise at least one member selected fromthe group of titanates, titanium chloride, tin chloride, zirconates,zirconium acetate, zirconium oxychloride, fluorides such as calciumfluoride, tin fluoride, titanium fluoride, zirconium fluoride; coppurouscompounds such as ammonium fluorosilicate, metal treated silicas (e.g.,Ludox(®)), nitrates such as aluminum nitrate; sulphates such asmagnesium sulphate, sodium sulphate, zinc sulphate, and copper sulphate;lithium compounds such as lithium acetate, lithium bicarbonate, lithiumcitrate, lithium metaborate, lithium vanadate, lithium tungstate, amongothers. Examples of commercially available rinses comprise at least onemember selected from the group of Aqualac® (urethane containing aqueoussolution), W86®, W87®, B37®, T01S, E₁₀®, among others (a heat curedcoating supplied by the Magni® Group), JS2030S (sodium silicatecontaining rinse supplied by MacDermid Incorporated), JS2040I (amolybdenum containing rinse also supplied by MacDermid Incorporated),EnSeal® C-23 (an acrylic based coating supplied by Enthone), Enthone®C-40 (a pigmented coating supplied Enthone), among others. One specificrinse comprises water, water dispersible urethane, and at least onesilicate, e.g., refer to commonly assigned U.S. Pat. No. 5,871,668;hereby incorporated by reference. While the rinse can be employed neat,normally the rinse will be dissolved, diluted or dispersed within 3sanother medium such as water, organic solvents, among others. While theamount of rinse employed depends upon the desired results, normally therinse comprises about 0.1 wt % to about 50 wt. % of the rinse medium.The rinse can be employed as multiple applications and, if desired,heated.

[0025] The metal surface refers to a metal article or body as well as anon-metallic or an electrically conductive member having an adheredmetal or conductive layer.

[0026] While any suitable surface can be treated by the inventiveprocess, examples of suitable metal surfaces comprise at least onemember selected from the group consisting of galvanized surfaces,sheradized surfaces, zinc, iron, steel, brass, copper, nickel, tin,aluminum, lead, cadmium, magnesium, alloys thereof such as zinc-nickelalloys, zinc-cobalt alloys, zinc-iron alloys, among others. If desired,the mineral layer can be formed on a non-conductive substrate having atleast one surface coated with an electrically conductive material, e.g.,a metallized polymeric article or sheet, ceramic materials coated orencapsulated within a metal, among others. Examples of metallizedpolymer comprise at least one member selected from the group ofpolycarbonate, acrylonitrile butadiene styrene (ABS), rubber, silicone,phenolic, nylon, PVC, polyimide, melamine, polyethylene, polyproplyene,acrylic, fluorocarbon, polysulfone, polyphenyene, polyacetate,polystyrene, epoxy, among others. Conductive surfaces can also includecarbon or graphite as well as conductive polymers (polyaniline forexample).

[0027] The metal surface can possess a wide range of sizes andconfigurations, e.g., fibers, coils, chopped wires, drawn wires or wirestrand/rope, rods, couplers (e.g., hydraulic hose couplings), fibers,particles, fasteners (including industrial and residential hardware),brackets, nuts, bolts, rivets, washers, among others. The limitingcharacteristic of the inventive process to treat a metal surface isdependent upon the ability of the electrical current to contact themetal surface. That is, similar to conventional electroplatingtechnologies, a mineral surface may be difficult to apply upon a metalsurface defining hollow areas or voids. This difficulty can be solved byusing a conformal anode.

[0028] The inventive process provides a flexible surface that cansurvive secondary processes, e.g., metal deformation for riveting,sweging, crimping, among other processes, and continue to providecorrosion protection. Such is in contrast to typical corrosioninhibitors such as chromates that tend to crack when the underlyingsurface is shaped. If desired, the flexible surface can be topcoated(e.g, with a heat cured epoxy), prior to secondary processing.

[0029] The inventive process provides a surface (e.g., mineral coating)that can enhance the surface characteristics of the metal or conductivesurface such as resistance to corrosion, protect carbon (fibers forexample) from oxidation, stress crack corrosion (e.g., stainless steel),hardness and improve bonding strength in composite materials, providedielectric layers, improve corrosion resistance of printedcircuit/wiring boards and decorative metal finishes, and reduce theconductivity of conductive polymer surfaces including application insandwich type materials.

[0030] The mineral coating can also affect the electrical and magneticproperties of the surface. That is, the mineral coating can impartelectrical resistance or insulative properties to the treated surface.By having an electrically non-conductive surface, articles having theinventive layer can reduce, if not eliminate, electro-galvanic corrosionin fixtures wherein current flow is associated with corrosion, e.g.,bridges, pipelines, among other articles.

[0031] In one aspect of the invention, the inventive process is employedfor improving the cracking and oxidation resistance of aluminum, copperor lead containing substrates. For example, lead, which is usedextensively in battery production, is prone to corrosion that in turncauses cracking, e.g., inter-granular corrosion. The inventive processcan be employed for promoting grain growth of aluminum, copper and leadsubstrates as well as reducing the impact of surface flaws. Withoutwishing to be bound by any theory or explanation, it is believed thatthe lattice structure of the mineral layer formed in accordance with theinventive process on these 3 types of substrates can be a partiallypolymerized silicate. These lattices can incorporate a disilicatestructure, or a chain silicate such as a pyroxene. A partiallypolymerized silicate lattice offers structural rigidity without beingbrittle. In order to achieve a stable partially polymerized lattice,metal cations would preferably occupy the lattice to provide chargestability. Aluminum has the unique ability to occupy either theoctahedral site or the tetrahedral site in place of silicon. The +3valence of aluminum would require additional metal cations to replacethe +4 valance of silicon. In the case of lead application, additionalcations could be, but are not limited to, a +2 lead ion.

[0032] In an aspect of the invention, an electrogalvanized panel, e.g.,a zinc surface, is coated electrolytically by being placed into anaqueous sodium silicate solution. After being placed into the silicatesolution, a mineral coating or film containing silicates is deposited byusing relatively low voltage potential (e.g., about 1 to about 24 vdepending upon the desired current density) and low current. The currentdensity will normally range from about 0.7 A/in2 to about 0.1 A/in2 at12 volt constant.

[0033] In one aspect of the invention, the workpiece is initiallyemployed as an anode and then electrically switched (or pulsed) to thecathode. By pulsing the voltage, the workpiece can be pre-treatedin-situ (prior to interaction with the electrolytic medium). Pulsing canalso increase the thickness of the film or layer formed upon theworkpiece. If desired, dopants (e.g., cations) can be present in theelectrolyte and deposited upon the surface by pulsing either prior to orfollowing mineralization.

[0034] In another aspect of the invention, the metal surface, e.g.,zinc, aluminum, steel, lead and alloys thereof; has an optionalpretreatment. By “pretreated” it is meant to refer to a batch orcontinuous process for conditioning the metal surface to clean it andcondition the surface to facilitate acceptance of the mineral orsilicate containing coating e.g., the inventive process can be employedas a step in a continuous process for producing corrosion resistant coilsteel. The particular pretreatment will be a function of composition ofthe metal surface and desired composition of mineral containingcoating/film to be formed on the surface. Examples of suitablepre-treatments comprise at least one of cleaning, e.g., sonic cleaning,activating, heating, degreasing, pickling, deoxidizing, shot glass beadblasting, sand blasting and rinsing. One suitable pretreatment processfor steel comprises:

[0035] 1) 2 minute immersion in a 3:1 dilution of Metal Prep 79 (ParkerAmehem),

[0036] 2) two deionized rinses,

[0037] 3) 10 second immersion in a pH 14 sodium hydroxide solution,

[0038] 4) remove excess solution and allow to air dry,

[0039] 5) 5 minute immersion in a 50% hydrogen peroxide solution,

[0040] 6) remove excess solution and allow to air dry.

[0041] In another aspect of the invention, the metal surface ispretreated by anodically cleaning the surface. Such cleaning can beaccomplished by immersing the work piece or substrate into a mediumcomprising silicates, hydroxides, phosphates and carbonates. By usingthe work piece as the anode in a DC cell and maintaining a current ofabout 10 A/ft2 to about 150 A/ft2, the process can generate oxygen gas.The oxygen gas agitates the surface of the workpiece while oxidizing thesubstrate's surface. The surface can also be agitated mechanically byusing conventional vibrating equipment. If desired, the amount of oxygenor other gas present during formation of the mineral layer can beincreased by physically introducing such gas, e.g., bubbling, pumping,among other means for adding gases.

[0042] In a further pre-treatment aspect of the invention, the workpiece is exposed to the inventive silicate medium as an anode therebycleaning the work piece (e.g., removing naturally occurring compounds).The work piece can then converted to the cathode and processed inaccordance with the inventive methods.

[0043] In a further aspect of the invention, the silicate medium ismodified to include at least one dopant material. The amount of dopantcan vary depending upon the properties of the dopant and desiredresults. Typically, the amount of dopant will range from about 0.001 wt.% to about 5 wt. % (or greater so long as the electrolyte is notadversely affected. Examples of suitable dopants comprise at least onemember selected from the group of water soluble salts, oxides andprecursors of tungsten, molybdenum, chromium, titanium, zircon,vanadium, phosphorus, aluminum, iron (e.g., iron chloride), boron,bismuth, gallium, tellurium, germanium, antimony, niobium (also known ascolumbium), magnesium and manganese, mixtures thereof, among others, andusually, salts and oxides of aluminum and iron. The dopant can compriseat least one of molybdenic acid, fluorotitanic acid and salts thereofsuch as titanium hydrofluoride, ammonium fluorotitanate, ammoniumfluorosilicate and sodium fluorotitanate; fluorozirconic acid and saltsthereof such as H₂ZrF₆, (NH₄)₂ZrF₆ and Na₂ZrF₆; among others.Alternatively, dopants can comprise at least one substantially waterinsoluble material such as electropheritic transportable polymers, PTFE,boron nitride, silicon carbide, silicon nitride, aluminum nitride,titanium carbide, diamond, titanium diboride, tugsten carbide, powderedmetals and metallic precursors such as zinc, among others.

[0044] The aforementioned dopants that can be employed for enhancing themineral layer formation rate, modifying the chemistry of the resultantlayer, as a diluent for the electrolyte or silicate containing medium,among others. Examples of such dopants are iron salts (ferrous chloride,sulfate, nitrate), aluminum fluoride, fluorosilicates (e.g., K2SiF6),fluoroaluminates (e.g., potassium fluoroaluminate such as K2AlF5-H20),mixtures thereof, among other sources of metals and halogens. The dopantmaterials can be introduced to the metal or conductive surface inpretreatment steps prior to electrodeposition, in post treatment stepsfollowing electrodeposition, and/or by alternating electrolytic contactsin solutions of dopants and solutions of silicates if the silicates willnot form a stable solution with the dopants, e.g., one or more watersoluble dopants. The presence of dopants in the electrolyte solution canbe employed to form tailored surfaces upon the metal or conductivesurface, e.g., an aqueous sodium silicate solution containing aluminatecan be employed to form a layer comprising oxides of silicon andaluminum.

[0045] Moreover, the aforementioned rinses can be modified byincorporating at least one dopant. The dopant can employed forinteracting or reacting with the treated surface. If desired, the dopantcan be dispersed in a suitable medium such as water and employed as arinse.

[0046] The silicate medium can be modified by adding water dispersibleor soluble polymers, and in some cases the electro-deposition solutionitself can be in the form of a flowable gel consistency having apredetermined viscosity. If utilized, the amount of polymer or waterdispersible materials normally ranges from about 0 wt. % to about 10 wt.%. Examples of polymers or water dispersible materials that can beemployed in the silicate medium comprise at least one member selectedfrom the group of acrylic copolymers (supplied commercially asCarbopol®), hydroxyethyl cellulose, clays such as bentonite, fumedsilica, solutions comprising sodium silicate (supplied commercially byMacDermid as JS2030S), among others. A suitable composition can beobtained in an aqueous composition comprising about 3 wt % N-gradeSodium Silicate Solution (PQ Corp), optionally about 0.5 wt % CarbopolEZ-2 (BF Goodrich), about 5 to about 10 wt. % fumed silica, mixturesthereof, among others. Further, the aqueous silicate solution can befilled with a water dispersible polymer such as polyurethane toelectro-deposit a mineral-polymer composite coating. The characteristicsof the electro-deposition solution can also be modified or tailored byusing an anode material as a source of ions which can be available forcodeposition with the mineral anions and/or one or more dopants. Thedopants can be useful for building additional thickness of theelectrodeposited mineral layer.

[0047] The silicate medium can also be modified by adding at least onediluent or electrolyte. Examples of suitable diluent comprise at leastone member selected from the group of sodium sulphate, surfactants,de-foamers, colorants/dyes, among others. The diluent (e.g., sodiumsulfate) can be employed for improving the electrical conductivity ofbath, reducing the affects of contaiments entering the silicate medium,reducing bath foam, among others. When the diluent is employed as adefoamer, the amount normally comprises less than about 5 wt. % of theelectrolyte, e.g., about 1 to about 2 wt. %. A diluent for affecting theelectrical conductivity of the bath or electrolyte is normally inemployed in an amount of about 0 wt. % to about 20 wt. %.

[0048] The following sets forth the parameters which may be employed fortailoring the inventive process to obtain a desirable mineral containingcoating:

[0049] 1. Voltage

[0050] 2. Current Density

[0051] 3. Apparatus or Cell Design

[0052] 4. Deposition Time

[0053] 5. Concentration of the silicate solution

[0054] 6. Type and concentration of anions in solution

[0055] 7. Type and concentration of cations in solution

[0056] 8. Composition/surface area of the anode

[0057] 9. Composition/surface area of the cathode

[0058] 10. Temperature

[0059] 11. Pressure

[0060] 12. Type and Concentration of Surface Active Agents

[0061] The specific ranges of the parameters above depend upon thesubstrate to be treated, and the intended composition to be deposited.Normally, the temperature of the electrolyte bath ranges from about 25to about 95 C, the voltage from about 6 to 24 volts, an electrolytesolution concentration from about 5 to about 15 wt. % silicate, thecurrent density ranges from about 0.025 A/in2 to about 0.60 A/in2,contact time with the electrolyte from about 10 seconds to about 50minutes and normally about 1 to about 15 minutes and anode to cathodesurface area ratio of about 0.5:1 to about 2:1. Items 1, 2, 7, and 8 canbe especially effective in tailoring the chemical and physicalcharacteristics of the coating. That is, items 1 and 2 can affect thedeposition time and coating thickness whereas items 7 and 8 can beemployed for introducing dopants that impart desirable chemicalcharacteristics to the coating. The differing types of anions andcations can comprise at least one member selected from the groupconsisting of Group I metals, Group II metals, transition and rare earthmetal oxides, oxyanions such as molybdate, phosphate, titanate, boronnitride, silicon carbide, aluminum nitride, silicon nitride, mixturesthereof, among others.

[0062] The typical process conditions will provide an environmentwherein hydrogen is evolved at the cathode and oxygen at the anode.Without wishing to be bound by any theory or explanation, it is believedthat the hydrogen evolution provides a relatively high pH at the surfaceto be treated. It is also believed that the oxygen reduced or deprivedenvironment along with a high pH can cause an interaction or a reactionat the surface of the substrate being treated. It is further believedthat zinc can function as a barrier to hydrogen thereby reducing, if noteliminating, hydrogen embrittlement being caused by operating theinventive process.

[0063] The inventive process can be modified by employing apparatus andmethods conventionally associated with electroplating processes.Examples of such methods include pulse plating, horizontal platingsystems, barrel, rack, adding electrolyte modifiers to the silicatecontaining medium, employing membranes within the bath, among otherapparatus and methods.

[0064] The inventive process can be modified by varying the compositionof the anode. Examples of suitable anodes comprise graphite, platinum,zinc, iron, steel, tantalum, niobium, titanium, nickel, irridium oxide,Monel® alloys, pallidium, alloys thereof, among others. The anode cancomprise a first material plated onto a second, e.g., platinum platedtitanium or platinum clad niobium mesh. The anode can possess anysuitable configuration, e.g., mesh adjacent to a barrel plating system.In some cases, the anode (e.g., iron or nickel) can release ions intothe electrolyte bath that can become incorporated within the minerallayer. Normally, ppm concentrations of anode ions are sufficient toaffect the mineral layer composition. If a dimensionally stable anode isdesired, then platinum plated niobium can be employed. In the event adimensionally stable anode requires cleaning, in most cases the anodecan be cleaned with sodium hydroxide solutions.

[0065] The inventive process can be practiced in any suitable apparatus.Examples of suitable apparatus comprise rack and barrel plating, brushplating, horizontal plating, continuous lengths, among other apparatusconventionally used in electroplating metals. Certain aspects of theinventive process are better understood by referring to the drawings.Referring now to FIG. 2, FIG. 2 illustrates a schematic drawing of oneprocess that employs one aspect of the inventive electrolytic method.The process illustrated in FIG. 2 can be operated in a batch orcontinuous process. The articles having a metal surface to be treated(or workpiece), if desired, can be cleaned by an acid such ashydrochloric acid, rinsed with water, and rinsed with an alkali such assodium hydroxide, rinsed again with water. The cleaning and rinsing canbe repeated as necessary. If desired the acid/alkali cleaning can bereplaced with a conventional sonic cleaning apparatus. The workpiece isthen subjected to the inventive electrolytic method thereby forming amineral coating upon at least a portion of the workpiece surface. Theworkpiece is removed from the electrolytic environment, dried and rinsedwith water, e.g, a layer comprising, for example, silica and/or sodiumcarbonate can be removed by rinsing.

[0066] Whether or not the workpiece is rinsed, the inventive process canimpart improved corrosion resistance without using chromates (hex ortrivalent). When a zinc surface is treated by the inventive process, thethickness (or total amount) of zinc can be reduced while achievingequivalent, if not improved, corrosion resistance. For example, whenexposing a steel article to a zinc plating environment for a period ofabout 2.5 to about 30 minutes and then to the inventive process for aperiod of about 2.5 to about 30 minutes white rust first occurs fromabout 24 hours to about 120 hours (when tested in accordance with ASTMB-117), and red rust failure occurs from about 100 to about 800 hours.As a result, the inventive process permits tailoring the amount of zincto a desired level of corrosion resistance. If desired, the corrosionresistance can be improved by applying at least one topcoating.

[0067] The inventive process also imparts improved torque tensionproperties in comparison to conventional chromate processes (hex ortrivalent). Wilson-Garner M10 bolts were coated with conventional zincand yellow hexavalent chromate, and treated in accordance with theinventive process. The torque tension of these bolts was tested inaccordance with test protocol USCAR-11 at forces from about 20,000 toabout 42,300 Newtons. The standard deviation for the peak torque for theconventional zinc/yellow chromate treated bolts was about 5.57 Nm with athree-sigma range of about 33.4, and about 2.56 Nm with a three-sigmarange of 15.4 for bolts treated in accordance with the inventiveprocess.

[0068] Depending upon the intended usage of the workpiece treated by theinventive method, the workpiece can be coated with a secondary coatingor layer. Alternatively, the treated workpiece can be rinsed (asdescribed above) and then coated with a secondary coating or layer.Examples of such secondary coatings or layers comprise one or moremembers of acrylic coatings (e.g., IRILAC®), silanes, latex, urethane,epoxies, silicones, alkyds, phenoxy resins (powdered and liquid forms),radiation curable coatings (e.g., UV curable coatings), lacquer,shellac, linseed oil, among others. Secondary coatings can be solvent orwater borne systems. The secondary coatings can be applied by using anysuitable conventional method such as immersing, dip-spin, spraying,among other methods. The secondary coatings can be cured by any suitablemethod such as UV exposure, heating, allowed to dry under ambientconditions, among other methods. An example of UV curable coating isdescribed in U.S. Pat. Nos. 6,174,932 and 6,057,382; hereby incorporatedby reference. Normally, the surface formed by the inventive process willbe rinsed, e.g., with at least one of deionized water, silane or acarbonate, prior to applying a topcoat. The secondary coatings can beemployed for imparting a wide range of properties such as improvedcorrosion resistance to the underlying mineral layer, reduce torquetension, a temporary coating for shipping the treated workpiece,decorative finish, static dissipation, electronic shielding, hydrogenand/or atomic oxygen barrier, among other utilities. The mineral coatedworkpiece, with or without the secondary coating, can be used as afinished product or a component to fabricate another article.

[0069] Without wishing to be bound by any theory or explanation a silicacontaining layer can be formed upon the mineral. The silica containinglayer can be chemically or physically modified and employed as anintermediate or tie-layer. The tie-layer can be used to enhance bondingto paints, coatings, metals, glass, among other materials contacting thetie-layer. This can be accomplished by binding to the top silicacontaining layer one or more materials which contain alkyl, fluorine,vinyl, epoxy including two-part epoxy and powder paint systems, silane,hydroxy, amino, mixtures thereof, among other functionalities reactiveto silica or silicon hydroxide. Alternatively, the silica containinglayer can be removed by using conventional cleaning methods, e.g,rinsing with de-ionized water. The silica containing tie-layer can berelatively thin in comparison to the mineral layer 100-500 angstromscompared to the total thickness of the mineral which can be 1500-2500angstroms thick. If desired, the silica containing layer can bechemically and/or physically modified by employing the previouslydescribed post-treatments, e.g., exposure to at least one carbonatesource. The post-treated surface can then be contacted with at least oneof the aforementioned secondary coatings, e.g, a heat cured epoxy.

[0070] In another aspect, the mineral without or without theaforementioned silica layer functions as an intermediate or tie-layerfor one or more secondary coatings, e.g., silane containing secondarycoatings. Examples of such secondary coatings and methods that can becomplimentary to the instant invention are described in U.S. Pat. Nos.5,759,629; 5,750,197; 5,539,031; 5,498,481; 5,478,655; 5,455,080; and5,433,976. The disclosure of each of these U.S. Patents is herebyincorporated by reference. For example, improved corrosion resistance ofa metal substrate can be achieved by using a secondary coatingcomprising at least one suitable silane in combination with amineralized surface. Examples of suitable silanes comprise at least onemembers selected from the group consisting of tetra-ortho-ethyl-silicate(TEOS), bis-1,2-(triethoxysilyl) ethane (BSTE), vinyl silane oraminopropyl silane, epoxy silanes, alkoxysilanes, among other organofunctional silanes. The silane can bond with the mineralized surface andthen the silane can cure thereby providing a protective top coat, or asurface for receiving an outer coating or layer. In some cases, it isdesirable to sequentially apply the silanes. For example, a steelsubstrate, e.g., a fastener, can be treated to form a mineral layer,allowed to dry, rinsed in deionized water, coated with a 5% BSTEsolution, coated again with a 5% vinyl silane solution, and powdercoated with a thermoset epoxy paint (Corvel 10-1002 by Morton) at athickness of 2 mils. The steel substrate was scribed using a carbide tipand exposed to ASTM B117 salt spray for 500 hours. After the exposure,the substrates were removed and rinsed and allowed to dry for 1 hour.Using a spatula, the scribes were scraped, removing any paint due toundercutting, and the remaining gaps were measured. The testedsubstrates showed no measurable gap beside the scribe.

[0071] One or more outer coatings or layers can be applied to thesecondary coating. Examples of suitable outer coatings comprise at leastone member selected from the group consisting of acrylics, epoxies,latex, urethanes, silanes, oils, gels, grease, among others. An exampleof a suitable epoxy comprises a coating supplied by The Magni® Group asB17 or B18 top coats, e.g, a galvanized article that has been treated inaccordance with the inventive method and contacted with at least onesilane and/or ammonium zirconium carbonate and top coated with a heatcured epoxy (Magni® B18) thereby providing a chromate free corrosionresistant article. By selecting appropriate rinses, secondary and outercoatings for application upon the mineral, a corrosion resistant articlecan be obtained without chromating or phosphating. Such a selection canalso reduce usage of zinc to galvanize iron containing surfaces, e.g., asteel surface is mineralized, coated with a silane containing coatingand with an outer coating comprising an epoxy.

[0072] While the above description places particular emphasis uponforming a mineral containing layer upon a metal surface, the inventiveprocess can be combined with or replace conventional metal pre or posttreatment and/or finishing practices. Conventional post coating bakingmethods can be employed for modifying the physical characteristics ofthe mineral layer, remove water and/or hydrogen, among othermodifications. The inventive mineral layer can be employed to protect ametal finish from corrosion thereby replacing conventional phosphatingprocess, e.g., in the case of automotive metal finishing the inventiveprocess could be utilized instead of phosphates and chromates and priorto coating application e.g., E-Coat. Further, the aforementioned aqueousmineral solution can be replaced with an aqueous polyurethane basedsolution containing soluble silicates and employed as a replacement forthe so-called automotive E-coating and/or powder painting process. Themineral forming process can be employed for imparting enhanced corrosionresistance to electronic components, e.g., such as the electric motorshafts as demonstrated by Examples 10-11. The inventive process can alsobe employed in a virtually unlimited array of end-uses such as inconventional plating operations as well as being adaptable to fieldservice. For example, the inventive mineral containing coating can beemployed to fabricate corrosion resistant metal products thatconventionally utilize zinc as a protective coating, e.g., automotivebodies and components, grain silos, bridges, among many other end-uses.

[0073] Moreover, depending upon the dopants and concentration thereofpresent in the mineral deposition solution, the inventive process canproduce microelectronic films, e.g., on metal or conductive surfaces inorder to impart enhanced electrical/magnetic and corrosion resistance,or to resist ultraviolet light and monotomic oxygen containingenvironments such as outer space.

[0074] In another aspect of the invention, the inventive process can beused to produce a surface that reduces, if not eliminates, molten metaladhesion (e.g., by reducing intermetallic formation). Without wishing tobe bound by any theory or explanation, it is believed that the inventiveprocess provides an ablative and/or a reactive film or coating upon anarticle or a member having its surface treated by the inventive processthat can interact or react with molten metal thereby reducing adhesionto the bulk article. For example, the inventive process can provide aniron or zinc silicate film or layer upon a substrate in order to shieldor isolate the substrate from molten metal contact (e.g., moltenaluminum or magnesium). The ability to prevent molten metal adhesion isdesirable when die casting aluminum over zinc cores, die castingaluminum for electronic components, among other uses. The molten metaladhesion can be reduced further by applying one of the aforementionedtopcoatings, e.g. Magni® B18, acrylics, polyesters, among others.

[0075] The following Examples are provided to illustrate certain aspectsof the invention and it is understood that such an Example does notlimit the scope of the invention as defined in the appended claims. Thex-ray photoelectron spectroscopy (ESCA) data in the following Examplesdemonstrate the presence of a unique metal disilicate species within themineralized layer, e.g., ESCA measures the binding energy of thephotoelectrons of the atoms present to determine bondingcharacteristics.

EXAMPLE 1

[0076] The following apparatus and materials were employed in thisExample:

[0077] Standard Electrogalvanized Test Panels, ACT Laboratories

[0078] 10% (by weight) N-grade Sodium Silicate solution

[0079] 12 Volt EverReady battery

[0080] 1.5 Volt Ray-O-Vac Heavy Duty Dry Cell Battery

[0081] Triplett RMS Digital Multimeter

[0082] 30 μF Capacitor

[0083] 29.8 ΩQ Resistor

[0084] A schematic of the circuit and apparatus which were employed forpracticing the Example are illustrated in FIG. 1. Referring now to FIG.1, the aforementioned test panels were contacted with a solutioncomprising 10% sodium mineral and de-ionized water. A current was passedthrough the circuit and solution in the manner illustrated in FIG. 1.The test panels was exposed for 74 hours under ambient environmentalconditions. A visual inspection of the panels indicated that alight-gray colored coating or film was deposited upon the test panel.

[0085] In order to ascertain the corrosion protection afforded by themineral containing coating, the coated panels were tested in accordancewith ASTM Procedure No. B117. A section of the panels was covered withtape so that only the coated area was exposed and, thereafter, the tapedpanels were placed into salt spray. For purposes of comparison, thefollowing panels were also tested in accordance with ASTM Procedure No.B117, 1) Bare Electrogalvanized Panel, and 2) Bare ElectrogalvanizedPanel soaked for 70 hours in a 10% Sodium Mineral Solution. In addition,bare zinc phosphate coated steel panels(ACT B952, no Parcolene) and bareiron phosphate coated steel panels (ACT B1000, no Parcolene) weresubjected to salt spray for reference.

[0086] The results of the ASTM Procedure are listed in the Table below:Panel Description Hours in B117 Salt Spray Zinc phosphate coated steel 1Iron phosphate coated steel 1 Standard Bare Electrogalvanize Panel ≈120Standard Panel with Sodium Mineral ≈120 Soak Coated Cathode of theInvention 240+

[0087] The above Table illustrates that the instant invention forms acoating or film which imparts markedly improved corrosion resistance. Itis also apparent that the process has resulted in a corrosion protectivefilm that lengthens the life of electrogalvanized metal substrates andsurfaces.

[0088] ESCA analysis was performed on the zinc surface in accordancewith conventional techniques and under the following conditions:

[0089] Analytical conditions for ESCA: Instrument Physical ElectronicsModel 5701 LSci X-ray source Monochromatic aluminum Source power 350watts Analysis region 2 mm × 0.8 mm Exit angle* 50° Electron acceptanceangle ±7° Charge neutralization electron flood gun Charge correctionC-(C,H) in C 1s spectra at 284.6 eV

[0090] The silicon photoelectron binding energy was used tocharacterized the nature of the formed species within the mineralizedlayer that was formed on the cathode. This species was identified as azinc disilicate modified by the presence of sodium ion by the bindingenergy of 102.1 eV for the Si(2p) photoelectron.

EXAMPLE 2

[0091] This Example illustrates performing the inventiveelectrodeposition process at an increased voltage and current incomparison to Example 1.

[0092] Prior to the electrodeposition, the cathode panel was subjectedto preconditioning process:

[0093] 1) 2 minute immersion in a 3:1 dilution of Metal Prep 79 (ParkerAmchem),

[0094] 2) two de-ionized rinse,

[0095] 3) 10 second immersion in a pH 14 sodium hydroxide solution,

[0096] 4) remove excess solution and allow to air dry,

[0097] 5) 5 minute immersion in a 50% hydrogen peroxide solution,

[0098] 6) Blot to remove excess solution and allow to air dry.

[0099] A power supply was connected to an electrodeposition cellconsisting of a plastic cup containing two standard ACT cold roll steel(clean, unpolished) test panels. One end of the test panel was immersedin a solution consisting of 10% N grade sodium mineral (PQ Corp.) inde-ionized water. The immersed area (1 side) of each panel wasapproximately 3 inches by 4 inches (12 sq. in.) for a 1:1 anode tocathode ratio. The panels were connected directly to the DC power supplyand a voltage of 6 volts was applied for 1 hour. The resulting currentranged from approximately 0.7-1.9 Amperes. The resultant current densityranged from 0.05-0.16 amps/in².

[0100] After the electrolytic process, the coated panel was allowed todry at ambient conditions and then evaluated for humidity resistance inaccordance with ASTM Test No. D2247 by visually monitoring the corrosionactivity until development of red corrosion upon 5% of the panel surfacearea. The coated test panels lasted 25 hours until the first appearanceof red corrosion and 120 hours until 5% red corrosion. In comparison,conventional iron and zinc phosphated steel panels develop firstcorrosion and 5% red corrosion after 7 hours in ASTM D2247 humidityexposure. The above Examples, therefore, illustrate that the inventiveprocess offers an improvement in corrosion resistance over iron and zincphosphated steel panels.

EXAMPLE 3

[0101] Two lead panels were prepared from commercial lead sheathing andcleaned in 6M HCl for 25 minutes. The cleaned lead panels weresubsequently placed in a solution comprising 1 wt. % N-grade sodiumsilicate (supplied by PQ Corporation).

[0102] One lead panel was connected to a DC power supply as the anodeand the other was a cathode. A potentional of 20 volts was appliedinitially to produce a current ranging from 0.9 to 1.3 Amperes. Afterapproximately 75 minutes the panels were removed from the sodiumsilicate solution and rinsed with de-ionized water.

[0103] ESCA analysis was performed on the lead surface. The siliconphotoelectron binding energy was used to characterized the nature of theformed species within the mineralized layer. This species was identifiedas a lead disilicate modified by the presence of sodium ion by thebinding energy of 102.0 eV for the Si(2p) photoelectron.

EXAMPLE 4

[0104] This Example demonstrates forming a mineral surface upon analuminum substrate. Using the same apparatus in Example 1, aluminumcoupons (3″ x 6″) were reacted to form the metal silicate surface. Twodifferent alloys of aluminum were used, A1 2024 and A17075. Prior to thepanels being subjected to the electrolytic process, each panel wasprepared using the methods outlined below in Table A. Each panel waswashed with reagent alcohol to remove any excessive dirt and oils. Thepanels were either cleaned with Alumiprep 33, subjected to anodiccleaning or both. Both forms of cleaning are designed to remove excessaluminum oxides. Anodic cleaning was accomplished by placing the workingpanel as an anode into an aqueous solution containing 5% NaOH, 2.4%Na₂CO3, 2% Na₂SiO₃, 0.6% Na₃PO₄, and applying a potential to maintain acurrent density of 100 mA/cm² across the immersed area of the panel forone minute.

[0105] Once the panel was cleaned, it was placed in a lliter beakerfilled with 800 mL of solution. The baths were prepared using de-ionizedwater and the contents are shown in the table below. The panel wasattached to the negative lead of a DC power supply by a wire whileanother panel was attached to the positive lead. The two panels werespaced 2 inches apart from each other. The potential was set to thevoltage shown on the table and the cell was run for one hour. TABLE AExample A B C D E F G H Alloy type 2024 2024 2024 2024 7075 7075 70757075 Anodic Yes Yes No No Yes Yes No No Cleaning Acid Wash Yes Yes YesYes Yes Yes Yes Yes Bath Solution Na₂SiO₃ 1% 10% 1% 10% 1% 10% 1% 10%H₂O₂ 1%  0% 0%  1% 1%  0% 0%  1% Potential 12 V 18 V 12 V 18 V 12 V 18 V12 V 18 V

[0106] ESCA was used to analyze the surface of each of the substrates.Every sample measured showed a mixture of silica and metal silicate.Without wishing to be bound by any theory or explanation, it is believedthat the metal silicate is a result of the reaction between the metalcations of the surface and the alkali silicates of the coating. It isalso believed that the silica is a result of either excess silicatesfrom the reaction or precipitated silica from the coating removalprocess. The metal silicate is indicated by a Si (2p) binding energy(BE) in the low 102 eV range, typically between 102.1 to 102.3. Thesilica can be seen by Si(2p) BE between 103.3 to 103.6 eV. The resultingspectra show overlapping peaks, upon deconvolution reveal bindingenergies in the ranges representative of metal silicate and silica.

EXAMPLE 5

[0107] This Example illustrates an alternative to immersion for creatingthe silicate containing medium.

[0108] An aqueous gel made by blending 5% sodium silicate and 10% fumedsilica was used to coat cold rolled steel panels. One panel was washedwith reagent alcohol, while the other panel was washed in a phosphoricacid based metal prep, followed by a sodium hydroxide wash and ahydrogen peroxide bath. The apparatus was set up using a DC power supplyconnecting the positive lead to the steel panel and the negative lead toa platinum wire wrapped with glass wool. This setup was designed tosimulate a brush plating operation. The “brush” was immersed in the gelsolution to allow for complete saturation. The potential was set for 12Vand the gel was painted onto the panel with the brush. As the brushpassed over the surface of the panel, hydrogen gas evolution could beseen. The gel was brushed on for five minutes and the panel was thenwashed with deionized water to remove any excess gel and unreactedsilicates.

[0109] ESCA was used to analyze the surface of each steel panel. ESCAdetects the reaction products between the metal substrate and theenvironment created by the electrolytic process. Every sample measuredshowed a mixture of silica and metal silicate. The metal silicate is aresult of the reaction between the metal cations of the surface and thealkali silicates of the coating. The silica is a result of either excesssilicates from the reaction or precipitated silica from the coatingremoval process. The metal silicate is indicated by a Si (2p) bindingenergy (BE) in the low 102 eV range, typically between 102.1 to 102.3.The silica can be seen by Si(2p) BE between 103.3 to 103.6 eV. Theresulting spectra show overlapping peaks, upon deconvolution revealbinding energies in the ranges representative of metal silicate andsilica.

EXAMPLE 6

[0110] Using the same apparatus described in Example 1, cold rolledsteel coupons (ACT laboratories) were reacted to form the metal silicatesurface. Prior to the panels being subjected to the electrolyticprocess, each panel was prepared using the methods outlined below inTable B. Each panel was washed with reagent alcohol to remove anyexcessive dirt and oils. The panels were either cleaned with Metalprep79 (Parker Amchem), subjected to anodic cleaning or both. Both forms ofcleaning are designed to remove excess metal oxides. Anodic cleaning wasaccomplished by placing the working panel as an anode into an aqueoussolution containing 5% NaOH, 2.4% Na₂CO₃, 2% Na₂SiO₃, 0.6% Na₃PO₄, andapplying a potential to maintain a current density of lOOmA/cm2 acrossthe immersed area of the panel for one minute.

[0111] Once the panel was cleaned, it was placed in a 1 liter beakerfilled with 800 mL of solution. The baths were prepared using de-ionizedwater and the contents are shown in the table below. The panel wasattached to the negative lead of a DC power supply by a wire whileanother panel was attached to the positive lead. The two panels werespaced 2 inches apart from each other. The potential was set to thevoltage shown on the table and the cell was run for one hour. TABLE BExample AA BB CC DD EE Substrate type CRS CRS CRS CRS¹ CRS² AnodicCleaning No Yes No No No Acid Wash Yes Yes Yes No No Bath SolutionNa₂SiO₃ 1% 10% 1% — — Potential (V) 14-24 6 (CV) 12V — — (CV) CurrentDensity 23 (CC) 23-10 85-48 — — (mA/cm²) B177 2 hrs 1 hr 1 hr 0.25 hr0.25 hr

[0112] The electrolytic process was either run as a constant current orconstant voltage experiment, designated by the CV or CC symbol in thetable. Constant Voltage experiments applied a constant potential to thecell allowing the current to fluctuate while Constant Currentexperiments held the current by adjusting the potential. Panels weretested for corrosion protection using ASTM B117. Failures weredetermined at 5% surface coverage of red rust.

[0113] ESCA was used to analyze the surface of each of the substrates.ESCA detects the reaction products between the metal substrate and theenvironment created by the electrolytic process. Every sample measuredshowed a mixture of silica and metal silicate. The metal silicate is aresult of the reaction between the metal cations of the surface and thealkali silicates of the coating. The silica is a result of either excesssilicates from the reaction or precipitated silica from the coatingremoval process. The metal silicate is indicated by a Si (2p) bindingenergy (BE) in the low 102 eV range, typically between 102.1 to 102.3.The silica can be seen by Si(2p) BE between 103.3 to 103.6 eV. Theresulting spectra show overlapping peaks, upon deconvolution revealbinding energies in the ranges representative of metal silicate andsilica.

EXAMPLE 7

[0114] Using the same apparatus as described in Example 1, zincgalvanized steel coupons (EZG 60G ACT Laboratories) were reacted to formthe metal silicate surface. Prior to the panels being subjected to theelectrolytic process, each panel was prepared using the methods outlinedbelow in Table C. Each panel was washed with reagent alcohol to removeany excessive dirt and oils.

[0115] Once the panel was cleaned, it was placed in a 1 liter beakerfilled with 800 mL of solution. The baths were prepared using de-ionizedwater and the contents are shown in the table below. The panel wasattached to the negative lead of a DC power supply by a wire whileanother panel was attached to the positive lead. The two panels werespaced approximately 2 inches apart from each other. The potential wasset to the voltage shown on the table and the cell was run for one hour.TABLE C Example A1 B2 C3 D5 Substrate type GS GS GS GS¹ Bath SolutionNa₂SiO₃ 10% 1% 10% — Potential (V) 6 (CV) 10 (CV) 18 (CV) — CurrentDensity 22-3 7-3 142-3 — (mA/cm²) B177 336 hrs 224 hrs 216 hrs 96 hrs

[0116] Panels were tested for corrosion protection using ASTM B117.Failures were determined at 5% surface coverage of red rust.

[0117] ESCA was used to analyze the surface of each of the substrates.ESCA detects the reaction products between the metal substrate and theenvironment created by the electrolytic process. Every sample measuredshowed a mixture of silica and metal silicate. The metal silicate is aresult of the reaction between the metal cations of the surface and thealkali silicates of the coating. The silica is a result of either excesssilicates from the reaction or precipitated silica from the coatingremoval process. The metal silicate is indicated by a Si (2p) bindingenergy (BE) in the low 102 eV range, typically between 102.1 to 102.3.The silica can be seen by Si(2p) BE between 103.3 to 103.6 eV. Theresulting spectra show overlapping peaks, upon deconvolution revealbinding energies in the ranges representative of metal silicate andsilica.

EXAMPLE 8

[0118] Using the same apparatus as described in Example 1, coppercoupons (C110 Hard, Fullerton Metals) were reacted to form themineralized surface. Prior to the panels being subjected to theelectrolytic process, each panel was prepared using the methods outlinedbelow in Table D. Each panel was washed with reagent alcohol to removeany excessive dirt and oils.

[0119] Once the panel was cleaned, it was placed in a 1 liter beakerfilled with 800 mL of solution. The baths were prepared using de-ionizedwater and the contents are shown in the table below. The panel wasattached to the negative lead of a DC power supply by a wire whileanother panel was attached to the positive lead. The two panels werespaced 2 inches apart from each other. The potential was set to thevoltage shown on the table and the cell was run for one hour. TABLE DExample AA1 BB2 CC3 DD4 EE5 Substrate type Cu Cu Cu Cu Cu¹ Bath SolutionNa₂SiO₃ 10% 10% 1% 1% — Potential (V) 12 (CV) 6 (CV) 6 (CV) 36 (CV) —Current Density 40-17 19-9 4-1 36-10 — (mA/cm²) B117 11 hrs 11 hrs 5 hrs5 hrs 2 hrs

[0120] Panels were tested for corrosion protection using ASTM B117.Failures were determined by the presence of copper oxide which wasindicated by the appearance of a dull haze over the surface.

[0121] ESCA was used to analyze the surface of each of the substrates.ESCA allows us to examine the reaction products between the metalsubstrate and the environment set up from the electrolytic process.Every sample measured showed a mixture of silica and metal silicate. Themetal silicate is a result of the reaction between the metal cations ofthe surface and the alkali silicates of the coating. The silica is aresult of either excess silicates from the reaction or precipitatedsilica from the coating removal process. The metal silicate is indicatedby a Si (2p) binding energy (BE) in the low 102 eV range, typicallybetween 102.1 to 102.3. The silica can be seen by Si(2p) BE between103.3 to 103.6 eV. The resulting spectra show overlapping peaks, upondeconvolution reveal binding energies in the ranges representative ofmetal silicate and silica.

EXAMPLE 9

[0122] An electrochemical cell was set up using a 1 liter beaker. Thebeaker was filled with a sodium silicate solution comprising 10 wt % Nsodium silicate solution (PQ Corp). The temperature of the solution wasadjusted by placing the beaker into a water bath to control thetemperature. Cold rolled steel coupons (ACT labs, 3×6 inches) were usedas anode and cathode materials. The panels are placed into the beakerspaced 1 inch apart facing each other. The working piece was establishedas the anode. The anode and cathode are connected to a DC power source.The table below shows the voltages, solutions used, time ofelectrolysis, current density, temperature and corrosion performance.TABLE E Silicate Bath Current Bath Corrosion Sample Conc. Temp VoltageDensity Time Hours # Wt % ° C. Volts mA/cm² min. (B117) I-A 10% 24 1244-48  5 1 I-B 10% 24 12 49-55  5 2 I-C 10% 37 12 48-60 30 71 I-D 10% 3912 53-68 30 5 I-F 10% 67 12 68-56 60 2 I-G 10% 64 12 70-51 60 75 I-H NANA NA NA NA 0.5

[0123] The panels were rinsed with de-ionized water to remove any excesssilicates that may have been drawn from the bath solution. The panelsunderwent corrosion testing according to ASTM B117. The time it took forthe panels to reach 5% red rust coverage (as determined by visualobservation) in the corrosion chamber was recorded as shown in the abovetable. Example I-H shows the corrosion results of the same steel panelthat did not undergo any treatment.

EXAMPLE 10

[0124] Examples 10, 11, and 14 demonstrate one particular aspect of theinvention, namely, imparting corrosion resistance to steel shafts thatare incorporated within electric motors. The motor shafts were obtainedfrom Emerson Electric Co. from St. Louis, Mo. and are used to hold therotor assemblies. The shafts measure 25 cm in length and 1.5 cm indiameter and are made from commercially available steel.

[0125] An electrochemical cell was set up similar to that in Example 9;except that the cell was arranged to hold the previously described steelmotor shaft. The shaft was set up as the cathode while two cold rolledsteel panels were used as anodes arranged so that each panel was placedon opposite sides of the shaft. The voltage and temperature wereadjusted as shown in the following table. Also shown in the table is thecurrent density of the anodes TABLE F Silicate Bath Current Bath SampleConc. Temp Voltage Density Time Corrosion # Wt % ° C. Volts mA/cm² min.Hours II-A 10% 27  6 17-9  60 3 II-B 10% 60 12 47-35 60 7 II-C 10% 75 1259-45 60 19 II-D 10% 93 12 99-63 60 24 II-F 10% 96 18 90-59 60 24 II-GNA NA NA NA NA 2 II-H NA NA NA NA NA 3

[0126] The shafts were rinsed with de-ionized water to remove any excesssilicates that may have been drawn from the bath solution. Example II-Ashowed no significant color change compared to Examples II-B-II-F due tothe treatment. Example II-B showed a slight yellow/gold tint. ExampleII-C showed a light blue and slightly pearlescent color. Example II-Dand II- showed a darker blue color due to the treatment. The panelsunderwent corrosion testing according to ASTM B117. The time it took forthe shafts to reach 5% red rust coverage in the corrosion chamber wasrecorded as shown in the table. Example II-G shows the corrosion resultsof the same steel shaft that did not undergo any treatment and ExampleII-H shows the corrosion results of the same steel shaft with acommercial zinc phosphate coating.

EXAMPLE 11

[0127] An electrochemical cell was set up similar to that in Example 10to treat steel shafts. The motor shafts were obtained from EmersonElectric Co. of St. Louis, Mo. and are used to hold the rotorassemblies. The shafts measure 25 cm in length and 1.5 cm in diameterand are made from commercially available steel. The shaft was set up asthe cathode while two cold rolled steel panels were used as anodesarranged so that each panel was placed on opposite sides of the shaft.The voltage and temperature were adjusted as shown in the followingtable. Also shown in the table is the current density of the anodesTABLE G Silicate Bath Current Bath Sample Conc. Temp Voltage DensityTime Corrosion # Wt % ° C. Volts mA/cm² min. Hours III-A 10% 92 12 90-5660 504 III-B 10% 73 12 50-44 60 552 III-C NA NA NA NA NA 3 III-D NA NANA NA NA 3

[0128] The shafts were rinsed with de-ionized water to remove any excesssilicates that may have been drawn from the bath solution. The panelsunderwent corrosion testing according to ASTM D2247. The time it too forthe shafts to reach 5% red to rust coverage in the corrosion chamber wasrecorded as shown in the table. Example III-C shows the corrosionresults of the same steel shaft that did not undergo any treatment andExample III-D shows the corrosion results of the same steel shaft with acommercial zinc phosphate coating.

EXAMPLE 12

[0129] An electrochemical cell was set up using a 1 liter beaker. Thesolution was filled with sodium silicate solution comprising 5,10, or 15wt % of N sodium silicate solution (PQ Corporation). The temperature ofthe solution was adjusted by placing the beaker into a water bath tocontrol the temperature. Cold rolled steel coupons (ACT labs, 3×6inches) were used as anode and cathode materials. The panels are placedinto the beaker spaced 1 inch apart facing each other. The working pieceis set up as the anode. The anode and cathode are connected to a DCpower source. The table below shows the voltages, solutions used, timeof electrolysis, current density through the cathode, temperature, anodeto cathode size ratio, and corrosion performance. TABLE H Silicate BathCurrent Bath Cor- Conc. Temp Voltage Density A/C Time rosion Sample # Wt% ° C. Volts mA/cm² ratio Min. Hours IV-1  5 55 12 49-51 0.5 15 2 IV-2 5 55 18 107-90  2 45 1 IV-3  5 55 24 111-122 1 30 4 IV-4  5 75 12 86-522 45 2 IV-5  5 75 18 111-112 1 30 3 IV-6  5 75 24 140-134 0.5 15 2 IV-7 5 95 12 83-49 1 30 1 IV-8  5 95 18 129-69  0.5 15 1 IV-9  5 95 24196-120 2 45 4 IV-10 10 55 12 101-53  2 30 3 IV-11 10 55 18 146-27  1 154 IV-12 10 55 24 252-186 0.5 45 7 IV-13 10 75 12 108-36  1 15 4 IV-14 1075 18 212-163 0.5 45 4 IV-15 10 75 24 248-90  2 30 16 IV-16 10 95 12168-161 0.5 45 4 IV-17 10 95 18 257-95  2 30 6 IV-18 10 95 24 273-75  115 4 IV-19 15 55 12 140-103 1 45 4 IV-20 15 55 18 202-87  0.5 30 4 IV-2115 55 24 215-31  2 15 17 IV-22 15 75 12 174-86  0.5 30 17 IV-23 15 75 18192-47  2 15 15 IV-24 15 75 24 273-251 1 45 4 IV-25 15 95 12 183-75  215 8 IV-26 15 95 18 273-212 1 45 4 IV-27 15 95 24 273-199 0.5 30 15IV-28 NA NA NA NA NA NA 0.5

[0130] The panels were rinsed with de-ionized water to remove any excesssilicates that may have been drawn from the bath solution. The panelsunderwent corrosion testing according to ASTM B117. The time it took forthe panels to reach 5% red rust coverage in the corrosion chamber wasrecorded as shown in the table. Example IV-28 shows the corrosionresults of the same steel panel that did not undergo any treatment. Thetable above shows the that corrosion performance increases with silicateconcentration in the bath and elevated temperatures. Corrosionprotection can also be achieved within 15 minutes. With a higher currentdensity, the corrosion performance can be enhanced further.

EXAMPLE 13

[0131] An electrochemical cell was set up using a 1 liter beaker. Thesolution was filled with sodium silicate solution comprising 10 wt % Nsodium silicate solution (PQ Corporation). The temperature of thesolution was adjusted by placing the beaker into a water bath to controlthe temperature. Zinc galvanized steel coupons (ACT labs, 3×6 inches)were used as cathode materials. Plates of zinc were used as anodematerial. The panels are placed into the beaker spaced 1 inch apartfacing each other. The working piece was set up as the anode. The anodeand cathode are connected to a DC power source. The table below showsthe voltages, solutions used, time of electrolysis, current density, andcorrosion performance. TABLE I Silicate Current Bath Sample Conc.Voltage Density Time Corrosion Corrosion # Wt % Volts mA/cm² min. (W)Hours (R) Hours V-A 10%  6  33-1 60 16 168 V-B 10%  3  6.5-1 60 17 168V-C 10% 18 107-8 60 22 276 V-D 10% 24 260-7 60 24 276 V-E NA NA NA NA 1072

[0132] The panels were rinsed with de-ionized water to remove any excesssilicates that may have been drawn from the bath solution. The panelsunderwent corrosion testing according to ASTM B117. The time when thepanels showed indications of pitting and zinc oxide formation is shownas Corrosion (W). The time it took for the panels to reach 5% red rustcoverage in the corrosion chamber was recorded as shown in the table asCorrosion (R). Example V-E shows the corrosion results of the same steelpanel that did not undergo any treatment.

EXAMPLE 14

[0133] An electrochemical cell was set up similar to that in Examples10-12 to treat steel shafts. The motor shafts were obtained from EmersonElectric Co. of St. Louis, Mo. and are used to hold the rotorassemblies. The shafts measure 25 cm in length and 1.5 cm in diameterand the alloy information is shown below in the table. The shaft was setup as the cathode while two cold rolled steel panels were used as anodesarranged so that each panel was placed on opposite sides of the shaft.The voltage and temperature were adjusted as shown in the followingtable. Also shown in the table is the current density of the anodesTABLE J Silicate Bath Current Bath Conc. Temp Voltage Density TimeCorrosion # Alloy Wt % ° C. Volts mA/cm² min. Hours VI-A 1018 10% 75 1294-66 30 16 VI-B 1018 10% 95 18 136-94  30 35 VI-C 1144 10% 75 12109-75  30 9 VI-D 1144 10% 95 18 136-102 30 35 VI-F 1215 10% 75 12 92-5230 16 VI-G 1215 10% 95 18 136-107 30 40

[0134] The shafts were rinsed with de-ionized water to remove any excesssilicates that may have been drawn from the bath solution. The panelsunderwent corrosion testing according to ASTM B117. The time it took forthe shafts to reach 5% red rust coverage in the corrosion chamber wasrecorded as shown in the table.

EXAMPLE 15

[0135] This Example illustrates using an electrolytic method to form amineral surface upon steel fibers that can be pressed into a finishedarticle or shaped into a preform that is infiltrated by anothermaterial.

[0136] Fibers were cut (0.20-0.26 in) from 1070 carbon steel wire, 0.026in. diameter, cold drawn to 260,000-280,000 PSI. 20 grams of the fiberswere placed in a 120 mL plastic beaker. A platinum wire was placed intothe beaker making contact with the steel fibers. A steel square 1 in by1 in, was held 1 inch over the steel fibers, and supported so not tocontact the platinum wire. 75 ml of 10% solution of sodium silicate(N-Grade PQ corp) in deionized water was introduced into the beakerthereby immersing both the steel square and the steel fibers and formingan electrolytic cell. A 12 V DC power supply was attached to this cellmaking the steel fibers the cathode and steel square the anode, anddelivered an anodic current density of up to about 3 Amps/sq. inch. Thecell was placed onto a Vortex agitator to allow constant movement of thesteel fibers. The power supply was turned on and a potential of 12 Vpassed through the cell for 5 minutes. After this time, the cell wasdisassembled and the excess solution was poured out, leaving behind onlythe steel fibers. While being agitated, warm air was blown over thesteel particles to allow them to dry.

[0137] Salt spray testing in accordance with ASTM B-117 was performed onthese fibers. The following table lists the visually determined resultsof the ASTM B-117 testing. TABLE K Treatment 1^(st) onset of corrosion5% red coverage UnCoated 1 hour 5 hours Electrolytic 24 hours 60

EXAMPLES 16-24

[0138] The inventive process demonstrated in Examples 16-24 utilized a 1liter beaker and a DC power supply as described in Example 2. Thesilicate concentration in the bath, the applied potential and bathtemperature have been adjusted and have been designated by table L-A.TABLE L-A Process silicate conc. Potential Temperature Time A 1 wt. %  6V 25 C. 30 min B 10% 12 V 75 C. 30 min C 15% 12 V 25 C. 30 min D 15% 18V 75 C. 30 min

EXAMPLE 16

[0139] To test the effect of metal ions in the electrolytic solutions,iron chloride was added to the bath solution in concentrations specifiedin the table below. Introducing iron into the solution was difficult dueto its tendency to complex with the silicate or precipitate as ironhydroxide. Additions of iron was also limited due to the acidic natureof the iron cation disrupting the solubility of silica in the alkalinesolution. However, it was found that low concentrations of iron chloride(<0.5%) could be added to a 20% N silicate solution in limitedquantities for concentrations less that 0.025 wt % FeCl3 in a 10 wt %silicate solution. Table L shows a matrix comparing electrolyticsolutions while keeping other conditions constant. Using an inert anode,the effect of the solution without the effect of any anion dissolutionwere compared. TABLE L-B Silicate Iron 1st Failure Process conc (%) Conc(%) Anode Red (5% red) B    10% 0 Pt 2 hrs 3 hrs B 10 0.0025 Pt 2 hrs 3hrs B 10 0.025 Pt 3 hrs 7 hrs B 10 0 Fe 3 hrs 7 hrs B 10 0.0025 Fe 2 hrs4 hrs B 10 0.025 Fe 3 hrs 8 hrs Control N/A N/A N/A 1 hr 1 hr ControlN/A N/A N/A 1 hr 1 hr

[0140] The trend shows increasing amounts of iron doped into the bathsolution using an inert platinum electrode will perform similarly to abath without doped iron, using an iron anode. This Example demonstratesthat the iron being introduced by the steel anode, which providesenhanced corrosion resistance, can be replicated by the introduction ofan iron salt solution.

EXAMPLE 17

[0141] Without wishing to be bound by any theory or explanation, it isbelieved that the mineralization reaction mechanism includes acondensation reaction. The presence of a condensation reaction can beillustrated by a rinse study wherein the test panel is rinsed after theelectrolytic treatment shown in Table M-A. Table M-A illustrates thatcorrosion times increase as the time to rinse also increases. It isbelieved that if the mineral layer inadequately cross-links orpolymerizes within the mineral layer the mineral layer can be easilyremoved in a water rinse. Conversely, as the test panel is dried for arelatively long period of time, the corrosion failure time improvesthereby indicating that a fully crossed-linked or polymerized minerallayer was formed. This would further suggest the possibility of afurther reaction stage such as the cross-linking reaction.

[0142] The corrosion resistance of the mineral layer can be enhanced byheating. Table M-B shows the effect of heating on corrosion performance.The performance begins to decline after about 600F. Without wishing tobe bound by any theory or explanation, it is believed that the heatinginitially improves cross-linking and continued heating at elevatedtemperatures caused the cross-linked layer to degrade. TABLE M-A Time ofrinse Failure time Immediately after process- still wet 1 hourImmediately after panel dries 2 hour 1 hour after panel dries 5 hour 24hours after panel dries 7 hour

[0143] TABLE M-B Process Heat Failure B  72 F. 2 hrs B 200 F. 4 hrs B300 F. 4 hrs B 400 F. 4 hrs B 500 F. 4 hrs B 600 F. 4 hrs B 700 F. 2 hrsB 800 F. 1 hr  D  72 F. 3 hrs D 200 F. 5 hrs D 300 F. 6 hrs D 400 F. 7hrs D 500 F. 7 hrs D 600 F. 7 hrs D 700 F. 4 hrs D 800 F. 2 hrs

EXAMPLE 18

[0144] In this Example the binding energy of a mineral layer formed onstainless steel is analyzed. The stainless steel was a ANSI 304 alloy.The samples were solvent washed and treated using Process B (a 10%silicate solution doped with iron chloride, at 75 C at 12 V for 30minutes). ESCA was performed on these treated samples in accordance withconventional methods. The ESCA results showed an Si(2p) binding energyat 103.4 eV.

[0145] The mineral surface was also analyzed by using Atomic ForceMicroscope (AFM). The surface revealed crystals were approximately 0.1to 0.5 μm wide.

EXAMPLE 19

[0146] The mineral layer formed in accordance with Example 18-method Bwas analyzed by using Auger Electron Spectroscopy (AES) in accordancewith conventional testing methods. The approximate thickness of thesilicate layer was determined to be about 5000 angstroms (500 nm) basedupon silicon, metal, and oxygen levels. The silica layer was less thanabout 500 angstroms (50 nm) based on the levels of metal relative to theamount of silicon and oxygen.

[0147] The mineral layer formed in accordance with Example 16 method Bapplied on a ANSI 304 stainless steel substrate. The mineral layer wasanalyzed using Atomic Force Microscopy (AFM) in accordance toconventional testing methods. AFM revealed the growth of metal silicatecrystals (approximately 0.5 microns) clustered around the areas of thegrain boundaries. AFM analysis of mineral layers of steel or zincsubstrate did not show this similar growth feature.

EXAMPLE 20

[0148] This Example illustrates the affect of silicate concentration onthe inventive process. The concentration of the electrolytic solutioncan be depleted of silicate after performing the inventive process. A 1liter 10% sodium silicate solution was used in an experiment to test thenumber of processes a bath could undergo before the reducing theeffectiveness of the bath. After 30 uses of the bath, using test panelsexposing 15 in², the corrosion performance of the treated panelsdecreased significantly.

[0149] Exposure of the sodium silicates to acids or metals can gel thesilicate rendering it insoluble. If a certain minimum concentration ofsilicate is available, the addition of an acid or metal salt willprecipitate out a gel. If the solution is depleted of silicate, or doesnot have a sufficient amount, no precipitate should form. A variety ofacids and metal salts were added to aliquots of an electrolytic bath.After 40 runs of the inventive process in the same bath, the mineralbarrier did not impart the same level of protection. This Exampleillustrates that iron chloride and zinc chloride can be employed to testthe silicate bath for effectiveness. TABLE N Solution Run 0 Run 10 Run20 Run 30 Run 40 0.1% FeCl3  2 drops − − − − − 10 drops + Trace Tracetrace trace  1 mL + + + + trace 10% FeCl3  2 drops + + + + + 10 dropsThick Thick Thick not as thick not as thick 0.05% ZnSO4  2 drops − − − −− 10 drops − − − − − 5% ZnSO4  2 drops + + + + + 10 drops + + + + finer0.1% ZnCl2  2 drops + + + + − 10 drops + + + + not as thick 10% ZnCl2  2drops + + + + finer 10 drops + + + + + 0.1% HCl  2 drops − − − − − 10drops − − − − − 10% HCl  2 drops − − − − − 10 drops − − − − − 0.1%K3Fe(CN)6  2 drops − − − − − 10 drops − − − − − 10% K3Fe(CN)6  2 drops −− − − − 10 drops − − − − −

EXAMPLE 21

[0150] This Example compares the corrosion resistance of a mineral layerformed in accordance with Example 16 on a zinc containing surface incomparison to an iron (steel) containing surface. Table 0 shows a matrixcomparing iron (cold rolled steel-CRS) and zinc (electrogalzanizedzinc-EZG) as lattice building materials on a cold rolled steel substrateand an electrozinc galvanized substrate. The results comparing rinsingare also included on Table O. Comparing only the rinsed samples, greatercorrosion resistance is obtained by employing differing anode materials.The Process B on steel panels using iron anions provides enhancedresistance to salt spray in comparison to the zinc materials. TABLE OSubstrate Anode Treatment Rinse 1st White 1st Red Failure CRS Fe B None1 2 CRS Fe B DI 3 24 CRS Zn B None 1 1 CRS Zn B DI 2 5 EZG Zn B None 1240 582 EZG Zn B DI 1 312 1080 EZG Fe B None 1 312 576 EZG Fe B DI 24312 864 CRS Control Control None 2 2 EZG Control Control None 3 168 192

EXAMPLE 22

[0151] This Example illustrates using a secondary layer upon the minerallayer in order to provide further protection from corrosion (a secondarylayer typically comprises compounds that have hydrophilic componentswhich can bind to the mineral layer).

[0152] The electronic motor shafts that were mineralized in accordancewith Example 10 were contacted with a secondary coating. The twocoatings which were used in the shaft coatings weretetra-ethyl-ortho-silicate (TEOS) or an organofunctional silane (VS).The affects of heating the secondary coating are also listed in TableP-A and P-B. Table P-A and P-B show the effect of TEOS and vinyl silaneson the inventive B Process. TABLE P-A TEOS 150° C. 1st Treatment ED TimeDry Rinse Dip Heat Red Failure B 10 min None No No no 3 hrs  5 hrs B 10min None No No yes 7 hrs 10 hrs B 30 min None No No no 3 hrs  5 hrs B 30min None No No yes 6 hrs 11 hrs B 10 min Yes No Yes no 3 hrs  3 hrs B 30min Yes No Yes yes 3 hrs  4 hrs B 10 min 1 hr No Yes no 1 hr   3 hrs B10 min 1 hr No Yes yes 7 hrs 15 hrs B 10 min 1 hr Yes Yes no 5 hrs  6hrs B 10 min 1 hr Yes Yes yes 3 hrs  4 hrs B 10 min 1 day No Yes no 3hrs 10 hrs B 10 min 1 day No Yes yes 3 hrs 17 hrs B 10 min 1 day Yes Yesno 4 hrs  6 hrs B 10 min 1 day Yes Yes yes 3 hrs  7 hrs B 30 min 1 hr NoYes no 6 hrs 13 hrs B 30 min 1 hr No Yes yes 6 hrs 15 hrs B 30 min 1 hrYes Yes no 3 hrs  7 hrs B 30 min 1 hr Yes Yes yes 2 hrs  6 hrs B 30 min1 day No Yes no 6 hrs 10 hrs B 30 min 1 day No Yes yes 6 hrs 18 hrs B 30min 1 day Yes Yes no 6 hrs  6 hrs B 30 min 1 day Yes Yes yes 4 hrs  7hrs Control 0 0 No No No 5 hrs  5 hrs Control 0 0 No No No 5 hrs  5 hrs

[0153] TABLE P-B Treatment Rinse Bake Test 1st Red Failure B DI No Salt3 10 B DI 150c Salt 3 6 B A151 No Salt 4 10 B A151 150c Salt 2 10 B A186No Salt 4 12 B A186 150c Salt 1 7 B A187 No Salt 2 16 B A187 150c Salt 216 Control None None Salt 1 1

[0154] Table P-A illustrates that heat treating improves corrosionresistance. The results also show that the deposition time can beshortened if used in conjunction with the TEOS. TEOS and heatapplication show a 100% improvement over standard Process B. The use ofvinyl silane also is shown to improve the performance of the Process B.One of the added benefits of the organic coating is that itsignificantly reduces surface energy and repels water.

EXAMPLE 23

[0155] This Example illustrates evaluating the inventive process forforming a coating on bare and galvanized steel was evaluated as apossible phosphate replacement for E-coat systems. The evaluationconsisted of four categories: applicability of E-coat over the mineralsurface; adhesion of the E-coat; corrosion testing of mineral/E-coatsystems; and elemental analysis of the mineral coatings. Four mineralcoatings (Process A, B, C, D) were evaluated against phosphate controls.The e-coat consisted of a cathodically applied blocked isocyanate epoxycoating. TABLE Q Process SiO3 conc. Potential Temperature Time A  1%  6V 25 C. 30 min B 10% 12 V 75 C. 30 min C 15% 12 V 25 C. 30 min D 15% 18V 75 C. 30 min

[0156] It was found that E-coat could be uniformly applied to themineral surfaces formed by processes A-D with the best applicationoccurring on the mineral formed with processes A and B. It was alsofound that the surfaces A and B had no apparent detrimental effect onthe E-coat bath or on the E-coat curing process. The adhesion testingshowed that surfaces A, B, and D had improved adhesion of the E-coat toa level comparable with that of phosphate. Similar results were seen insurfaces C and D over galvanized steel. Surfaces B and D generallyshowed more corrosion resistance than the other variations evaluated.

[0157] To understand any relation between the coating and performance,elemental analysis was done. It showed that the depth profile ofcoatings B and D was significant, >5000 angstroms.

EXAMPLE 24

[0158] This Example demonstrates the affects of the inventive process onstress corrosion cracking. These tests were conducted to examine theinfluence of the inventive electrolytic treatments on the susceptibilityof AISI 304 stainless steel coupons to stress cracking. The testsrevealed improvement in pitting resistance for samples following theinventive process. Four corrosion coupons of AISI 304 stainless steelwere used in the test program. One specimen was tested without surfacetreatment. Another specimen was tested following an electrolytictreatment of Example 16, method B.

[0159] The test specimens were exposed according to ASTM G48 Method A(Ferric Chloride Pitting Test). These tests consisted of exposures to aferric chloride solution (about 6 percent by weight) at room temperaturefor a period of 72 hours.

[0160] The results of the corrosion tests are given in Table R. Thecoupon with the electrolytic treatment suffered mainly end grain attackas did the non-treated coupon. TABLE R Results of ASTM G48 Pitting TestsMax. Pit Depth Pit Penetration Rate (mils) (mpy) Comments 3.94 479Largest pits on edges. Smaller pits on surface.

[0161] ASTM G-48, 304 stainless steel Exposure to Ferric Chloride, 72Hours, Ambient Temperature WEIGHT SUR- INITIAL WEIGHT AFTER SCALE WEIGHTFACE CORR. WEIGHT AFTER TEST WEIGHT LOSS AREA TIME DENSITY RATE (g) TEST(g) CLEANED (g) (g) (g)* (sq. in) (hrs) (g/cc) (mpy) 28.7378 28.280328.2702 −0.4575 0.4676 4.75 72.0 7.80 93.663

EXAMPLE 25

[0162] This example illustrates the improved adhesion and corrosionprotection of the inventive process as a pretreatment for paint topcoats. A mineral layer was formed on a steel panel in accordance toExample 16, process B. The treated panels were immersed in a solution of5% bis-1,2-(triethoxysilyl) ethane (BSTE-Witco) allowed to dry and thenimmerse in a 2% solution of vinyltriethoxysilane (Witco) or 2%Gammaglycidoxypropyl-trimethoxysilane (Witco). For purposes ofcomparison, a steel panel treated only with BSTE followed by vinylsilane, and a zinc phosphate treated steel panel were prepared. All ofthe panels were powder coated with a thermoset epoxy paint (Corvel10-1002 by Morton) at a thickness of 2 mils. The panels were scribedusing a carbide tip and exposed to ASTM B117 salt spray for 500 hours.After the exposure, the panels were removed and rinsed and allowed todry for 1 hour. Using a spatula, the scribes were scraped, removing anypaint due to undercutting, and the remaining gaps were measured. Thezinc phosphate and BSTE treated panels both performed comparably showingan average gap of 23 mm. The mineralized panels with the silane posttreatment showed no measurable gap beside the scribe. The mineralizedprocess performed in combination with a silane treatment showed aconsiderable improvement to the silane treatment alone. This Exampledemonstrates that the mineral layer provides a surface or layer to whichthe BSTE layer can better adhere.

EXAMPLE 26

[0163] This Example illustrates that the inventive mineral layer formedupon a metal containing surface can function as an electrical insulator.A Miller portable spot welder model # AASW 1510M/110V input/4450Secondary amp output was used to evaluate insulating properties of amineral coated steel panel. Control panels of cold rolled steel (CRS),and 60 g galvanized steel were also evaluated. All panels were 0.032″thickness. Weld tips were engaged, and held for an approximately 5.0second duration. The completed spot welds were examined for bonding,discoloration, and size of weld. The CRS and galvanized panels exhibiteda good bond and had a darkened spot weld approximately 0.25″ indiameter. The mineral coated steel panel did not conduct an amount ofelectricity sufficient to generate a weld, and had a slightly discolored0.06″ diameter circle.

EXAMPLE 27

[0164] This Example illustrates forming the inventive layer upon a zincsurface obtained by a commercially available sherardization process.

[0165] A 2 liter glass beaker was filled with 1900 mL of mineralizingsolution comprising 10 wt. % N sodium silicate solution (PQ Corp.) and0.001 wt. % Ferric Chloride. The solution was heated to 75 C on astirring hot plate. A watch glass was placed over the top of the beakerto minimize evaporative loss while the solution was heating up. Twostandard ACT cold roll steel (100008) test panels (3 in.×6 in.×0.032in.) were used as anodes and hung off of copper strip contacts hangingfrom a {fraction (3/16)} in. diameter copper rod. The cathode was aSherardized washer that was 1.1875 inches in diameter and 0.125 inchesthick with a 0.5 inch center hole. The washer and steel anodes wereconnected to the power supply via wires with stainless steel gatorclips. The power supply was a Hull Cell rectifier (Tri-Electronics). Thewasher was electrolytically treated for 15 minutes at a constant 2.5volts (˜1 A/sq. inch current density). The washer was allowed to dry atambient conditions after removal from the CM bath. Subsequent salt spraytesting (ASTM-B117 Method) was performed and compared to an untreatedcontrol washer with results as follows: Hours to First Red SampleCorrosion Hours to 5% Red Corrosion Control Washer 144 192 MineralizedWasher 360 1416

EXAMPLE 28

[0166] This Example demonstrates using post-treatment process forimproving the properties of the inventive layer.

[0167] A tank containing 25 gallons of mineralizing solution comprising10 wt. % N sodium silicate solution (PQ Corp.) and 0.001 wt. % FerricChloride was heated to 75 C with immersion heaters. Six standard ACTcold roll steel (100008) test panels (3 in.×6 in.×0.032 in.) were usedas anodes and hung off of copper strip contacts hanging from a {fraction(3/16)} in. diameter copper rod. The {fraction (3/16)} inch copper rodcontacted the 0.5 inch copper anode bus bar which was connected to therectifier. Three standard ACT Electrogalvanized steel test panels (ACTE60 EZG 2 side 03×06×0.030 inches) were hung between the two sets ofthree steel anodes with the anodes approximately 3 inches from theelectrogalvanized steel test panels. The electrogalvanized steel panelswere connected to the cathode bus bar. The Electrogalvanized test panelswere treated for 15 minutes at a constant 12 volts. The current wasinitially approximately 40 amps and decayed to approximately 25 ampsafter 15 minutes of exposure. The panels were post treated in aqueoussolutions as follows: Sample # Immediate Rinse Dry Treatment Solution 1No Yes Ammonium Zirconyl Carbonate (Bacote 20 Diluted 1:4) 2 Yes NoAmmonium Zirconyl Carbonate (Bacote 20 Diluted 1:4) 3 No Yes AmmoniumZirconyl Carbonate (Bacote 20 Diluted 1:4) 4 No Yes 20 Vol % PhosphoricAcid 5 Yes No 20 Vol % Phosphoric Acid 6 No Yes None 7 No Yes 2.5 Vol %Phosphoric Acid 8 Yes No 2.5 Vol % Phosphoric Acid 9 No Yes None 10 NoYes 1.0 wt. % Ferric Chloride 11 Yes No 1.0 wt. % Ferric Chloride 12 NoYes 1.0 wt. % Ferric Chloride

[0168] As indicated above, some of the samples were rinsed and thentreated immediately and some of the samples were dried first and thentreated with the indicated aqueous solution. After drying, samples 3, 6,7 and 10 were spray painted with 2 coats of flat black (7776) PremiumRustoleum Protective Enamel. The final dry film coating thicknessaveraged 0.00145 inches. The painted test panels were allowed to dry atambient conditions for 24 hours and then placed in humidity exposure(ASTM-D2247) for 24 hours and then allowed to dry at ambient conditionsfor 24 hours prior to adhesion testing. The treated panels weresubjected to salt spray testing (ASTM-B117) or paint adhesion testing(ASTM D-3359) as indicated below: % Paint Hours To First Hours To 5%Sample Adhesion B117 Red B117 Red # Loss Corrosion Corrosion 1 — 288 4562 — 168 216 3  0 — — 4 — 144 216 5 —  96 120 6 100 — — 7 15-35 — — 8 — 72  96 9 — 192 288 10 15-35 — — 11 — 168 168 12 —  72  96

[0169] The above results show that the ammonium zirconyl carbonate had abeneficial effect on Both adhesion of subsequent coatings as well as animprovement in corrosion resistance of uncoated surfaces. The salt sprayresults indicate that the corrosion resistance was decreased byimmediate rinsing and exposure to the strong phosphoric acid.

EXAMPLE 29

[0170] This Example demonstrates the affects of the inventive process onstress corrosion cracking. These tests were conducted to examine theinfluence of the inventive electrolytic treatments on the susceptibilityof AISI 304 and 316 stainless steel coupons to stress cracking. Thetests revealed improvement in pitting resistance for samples followingthe inventive process. Three corrosion coupons steel were included ineach test group. The Mineralized specimen were tested following anelectrolytic treatment of Example 16, method B (15 minutes).

[0171] The test specimens were exposed according to ASTM G48 Method A(Ferric Chloride Pitting Test). These tests consisted of exposures to aferric chloride solution (about 6 percent by weight) at room temperaturefor a period of 72 hours.

[0172] The results of the corrosion tests are given in Table R. Thecoupon with the electrolytic treatment suffered mainly end grain attackas did the non-treated coupon. The results are as follows: Avg. Of PitAvg. Max. Ten Density Avg. Mass Mineral Pit Depth Deepest (pits/sq. Loss(g/sq. Material Treatment (μM) Pits (μM) cm) cm) AISI 304 No 2847 13104.1 0.034 AISI 304 Yes 2950 1503 0.2 0.020 AISI 316L No 2083 1049 2.50.013 AISI 316L Yes 2720  760 0.3 0.005

[0173] The mineralizing treatment of the instant invention effectivelyreduced the number of pits that occurred.

EXAMPLE 30

[0174] This Example demonstrates the effectiveness of the inventivemethod on improving the crack resistance of the underlying substrate.Nine U-Bend Stress corrosion specimens made from AISI 304 stainlesssteel were subjected to a heat sensitization treatment at 1200 F for 8hours prior to applying the mineral treatment as described in Example16, method B (5 and 15 minutes). Each test group contained three samplesthat were 8 inches long, two inches wide and {fraction (1/16)} inchesthick. After application of the mineral treatment, the samples wereplaced over a stainless steel pipe section and stressed. The exposuresequence was similar to that described in ASTM C692 and consisted ofapplying foam gas thermal insulation around the U-Bemd Specimens thatconformed to their shape. One assembled, 2.473 g/L NaCl solution wascontinuously introduced to the tension surface of the specimens throughholes in the insulation. The flow rate was regulated to achieve partialwet/dry conditions on the specimens. The pipe section was internallyheated using a cartidge heater and a heat transfer fluid and testtemperature controlled at 160 F. The test was run for a period of 100hours followed by a visual examination of the test specimens withresults as follows: Mineral Avg. Total Treatment AVG. Crack Mineral TimeNumber Length Material Treatment (Minutes) Of Cracks (In) AISI 304 No  08.7 1.373 AISI 304 Yes  5 2.7 0.516 AISI 304 Yes 15 4.3 1.330

[0175] The mineralization treatment of the instant invention effectivelyreduced the number and length of cracks that occurred.

EXAMPLE 31

[0176] This Example illustrates the improved heat and corrosionresistance of ACT zinc test panels treated in accordance with theinstant invention in comparison to conventional chromate treatments.HEAT EXPOSURE HOURS AND CORROSION RESISTANCE (ASTM B-117 SALT SPRAYEXPOSURE) AMBIENT (70 F.) 200 F./15 MINUTES 400 F./15 MINUTES 600 F./15MINUTES 700 F./15 MINUTES First First Failed First First Failed FirstFirst Failed First First Failed First First Failed White Red Red WhiteRed Red White Red Red White Red Red White Red Red Zinc Average 24 136212 24 204 276 24 123 187 24 119 204 24 60 162 Plated Control CM*Average 72 520 1128 72 620 1148 72 340 464 72 220 448 48 99 264 Zinc NoRinse CM* Average 72 736 1216 72 716 1320 72 295 1084 72 271 448 48 83247 Zinc Process A (Silane) Zinc Average 48 128 239 48 127 262 24 84 18124 84 153 24 52 278 Clear Chro- mate Zinc Average 420 1652 2200 424 13601712 48 202 364 24 93 168 24 24 170 Yellow Chro- mate Zinc Average 3121804 2336 294 1868 2644 48 331 576 36 97 168 24 76 236 Olive Drab Chro-mate

[0177] Cylinderical zinc plated conduit end-fitting sleeves measuringabout 1.5 in length by about 0.50 inch diameter were divided into sixgroups. One group was given no subsequent surface treatment. One groupwas treated with a commercially available clear chromate conversioncoating, one group was treated with a yellow chromate conversion and onegroup was treated with an olive-drab chromate conversion coating. Twogroups were charged cathodically in a bath comprising de-ionized waterand about 10 wt % N sodium silicate solution at 12.0 volts (70-80° C.)for 15 minutes. One of the cathodically charged groups was dried with nofurther treatment. The other group was rinsed successively in deionizedwater, a solution comprising 10 wt % denatured ethanol in deionizedwater with 2 vol. % 1,2 (Bis Triethoxysilyllethane [suppliedcommerically by Aldrich], and a solution comprising 10 wt % denaturedethanol in deionized water with 2 vol. % epoxy silane [suppliedcommcially as Silquest A-186 by OSF Specialties].

[0178] The six groups of fitting were each subdivided and exposed toeither (A) no elevated temp. (B) 200° F. for 15 min. (C) 400° F. for 15min. (D) 600° F. for 15 min. or (E) 700° F. for 15 minutes and tested insalt spray for ASTM-B117 until failure. Results are given above.

EXAMPLE 32

[0179] This Example illustrates a process comprising the inventiveprocess that is followed by a post-treatment. The post-treatmentcomprises contacting a previously treated article with an aqueous mediumcomprising water soluble or dispersible compounds.

[0180] The inventive process was conducted in an electrolyte that wasprepared by adding 349.98 g of N. sodium silicate solution to a processtank containing 2.8 L of deionized water. The solution was mixed for5-10 minutes. 0.1021 g of ferric chloride was mixed into 352.33 g ofdeionized water. Then the two solutions, the sodium silicate and ferricchloride, were combined in the processing tank with stirring. An amountof deionized water was added to the tank to make the final volume of thesolution 3.5 L. ACT zinc (egalv) panels were immersed in the electrolyteas the cathode for a period of about 15 minutes. The anode comprisedplatinum clad niobium mesh.

[0181] The following post-treatment mediums were prepared by adding theindicated amount of compound to de-ionized water:

[0182] A) Zirconium Acetate (200 g/L)

[0183] B) Zirconium Oxy Chloride (100 g/L)

[0184] C) Calcium Fluoride (8.75 g/L)

[0185] D) Aluminum Nitrate (200 g/L)

[0186] E) Magnesium Sulfate (100 g/L)

[0187] F) Tin (11) Fluoride (12 g/L)

[0188] G) Zinc Sulfate (100 g/L)

[0189] H) Titanium Fluoride (5 g/L)

[0190] I) Zirconium Fluoride (5 g/L)

[0191] J) Titanium Chloride (150 g/L)

[0192] K) Stannic Chloride (20 g/L)

[0193] The corrosion resistance of the post-treated zinc panels wastested in accordance with ASTM B-177. The results of the testing arelisted below. Hrs. First White Hrs. First Red Failed Zicronium AcetateZn  5  96  96 Zicronium Oxzychlorite Zn  5 120 120 Calcium Flouride Zn24  96  96 Aluminum Nitrate Zn 24 144 240 Magnesium Sulfate Zn 24 264456 Tin Fluoride Zn 24 288 312 Zinc Sulfate Zn  5  96  96 TitaniumFluoride Zn 24  72  72 Zirconium Fluoride Zn 24 144 264

EXAMPLES 33

[0194] This Example illustrates the addition of dopants to theelectrolyte (or bath) that is employed for operating the inventiveprocess. In each following example, the workpiece comprises the cathodeand the anode comprises platinum clad niobium mesh. The electrolyte wasprepared in accordance with the method Example 32 and the indicatedamount of dopant was added. An ACT test panel comprising zinc, iron or304 stainless steel was immersed in the electrolyte and the indicatedcurrent was introduced. Panel Zn Zn Fe Fe 30455 30455 Min- CurrentCurrent Current Current Current Current utes (A) (A) (A) (A) (A) (A)Dopant (Zirconium Acetate Bath, 200/L)  0 13.1 13.3 12.9 12.4 12.0 11.815 13.2 13.0 12.1 11.6 11.1 11.1 Bath 74-76 C. 74-76 74-76 74-76 74-7674-76 Temp Dopant (Zirconium Oxy Chloride Bath, 100 g/l)  0 11.2 11.211.3 11.1 10.5 11.2 15 10.9 10.5 10.3 10.1 10.0 10.6 Bath 74-76 C. 74-7674-76 74-76 74-76 74-76 Temp Dopant (Calcium Fluoride Bath 8.75 g/L)  011.2 11.0 11.0 10.7  9.2 12.1 15 11.0 10.8 10.4  9.7  9.0 11.5 Bath74-76 C. 74-76 74-76 74-76 74-76 74-76 Temp Dopant (Aluminum NitrateBath, 200 g/L)  0 12   12.9 12.5 12.2 11.8 11.4 15 13.3 12.7 12   11.711.1 11   Bath 74-76 C. 74-76 74-76 74-76 74-76 74-76 Temp Dopant(Magnesium Sulfate Bath, 100 g/L)  0 11.1 10.6 10.2 10.8 11.3 11.8 1510.5  9.9  9.9 10.5 10.6 10.9 Bath 74-76 C. 74-76 74-76 74-76 74-7674-76 Temp Dopant (Tin Flouride Bath, 12 grams/1L)  0 11   12.1 11.611.3 10.5 10.7 15 11.1 11.4 10.8 10    9.4  9.4 Bath 74-76 C. 74-7674-76 74-76 74-76 74-76 Temp Dopant (Zinc Sulflate Bath, 100 g/L)  011.3 10.9  9.9  9.3  8.5  9.3 15 10.1  9.7  8.9  8.3  7.9 8   Bath 74-76C. 74-76 74-76 74-76 74-76 74-76 Temp Dopant (Titanium Flouride Bath, 5g/L)  0 12   12.8 12.1 13.3 12.9 12.7 15 12.4 12.4 11.6 12.9 12.1 11.8Bath 74-76 C. 74-76 74-76 74-76 74-76 74-76 Temp Dopant (ZirconiumFlouride Bath, 5 g/L)  0 11.3 11.9 12.1 12.1 11.7 11.4 15 11.8 11.7 11.511.3 10.8 10.7 Bath 74-76 C. 74-76 74-76 74-76 74-76 74-76 Temp Dopant(Titanium (III) Chloride Bath, 150 g/L)  0 11.0  8.8  9.3 10.0 10.2 10.215  9.4  8.0  8.6  9.3  8.9  8.4 Bath 74-76 C. 74-76 74-76 74-76 74-7674-76 Temp Dopant (Stannic Chloride Bath, 20 g/1L)  0 10.7 10.2  9.5 9.7  9.6  9.3 15  9.3  9.1  8.8  8.6  8.3  7.9 Bath 74-76 C. 74-7674-76 74-76 74-76 74-76 Temp

THE FOLLOWING IS CLAIMED:
 1. A method for treating an electricallyconductive surface comprising: contacting at least the surface with amedium comprising at least one silicate and having a basic pH andwherein said medium is substantially free of chromates, introducing acurrent to said medium wherein said surface is employed as a cathode. 2.An aqueous medium for use in an electrically enhanced method fortreating a conductive surface comprising a combination comprisingde-ionized water, at least one silicate, at least one dopant and whereinthe medium has a basic pH.
 3. A method for forming a coating upon ametal or electrically conductive surface comprising: exposing thesurface to a first medium comprising an aqueous medium comprising atleast one water soluble silicate wherein said first medium has a basicpH, introducing a current to said first medium; and exposing the surfaceto a second medium comprising a combination a comprising water and atleast one water soluble compound selected from the group consisting ofchlorides, fluorides, nitrates, zironates, titanates, sulphates andwater soluble lithium compounds.
 4. The method of claim 1 wherein thesilicate containing medium comprises sodium silicate.
 5. The method ofclaim 1 wherein the surface comprises at least one member selected fromthe group consisting of copper, nickel, tin, zinc, aluminum, stainlesssteel and steel.
 6. The method of claim 1 wherein further comprising apost-treatment comprising contacting with at least one source ofcarbonate.
 7. The method of claim 6 wherein the source of at least onecarbonate comprises at least one member chosen from the group of lithiumcarbonate, lithium bicarbonate, sodium carbonate, sodium bicarbonate,potassium carbonate, potassium bicarbonate, rubidium carbonate, rubidiumbicarbonate, rubidium acid carbonate, cesium carbonate, ammoniumcarbonate, ammonium bicarbonate, ammonium carbamate and ammoniumzirconyl carbonate.
 8. The medium of claim 2 wherein a dimensionallystable anode is at least partially in contact with said medium.
 9. Themethod of claim 6 comprising applying at least one topcoating upon thepost-treated surface.
 10. The medium of claim 2 wherein the mediumcomprises greater than 3 wt. % of at least one silicate.
 11. The methodof claim 1 further comprising forming a layer comprising silica upon themineral.
 12. The medium of claim 3 wherein said water soluble compoundcomprises at least one member selected from the group consisting of fromthe group of titanium chloride, tin chloride, zirconium acetate,zirconium oxychloride, calcium fluoride, tin fluoride, titaniumfluoride, zirconium fluoride; ammonium fluorosilicate, aluminum nitrate;magnesium sulphate, sodium sulphate, zinc sulphate, copper sulphate;lithium acetate, lithium bicarbonate, lithium citrate, lithiummetaborate, lithium vanadate and lithium tungstate.
 13. The method ofclaim 8 wherein said anode comprises platinum.
 14. The method of claim 3wherein the silicate containing medium further comprises at least onedopant.
 15. The method of claim 14 wherein the dopant comprises at leastone member selected from the group consisting of molybdenum, chromium,titanium, zircon, vanadium, phosphorus, aluminum, iron, boron, bismuth,gallium, tellurium, germanium, antimony, niobium, magnesium, manganese,and their oxides and salts.
 16. The method of claim 3 wherein thesilicate containing medium further comprises a water dispersiblepolymer.
 17. The method of claim 14 wherein the dopant comprises theanode of the electrolytic environment.
 18. The method of claim 1 furthercomprising forming a secondary coating comprising at least one memberchosen from the group of latex, silanes, epoxies, silicone, urethanesand acrylics.
 19. The method of claim 7 wherein the carbonate sourcecomprises ammonium zirconyl carbonate.
 20. A product formed according tothe method of claim 1 or 3 wherein said product comprises a zinc surfaceand has an ASTM B117 exposure to white rust of greater than 72 hours.